1 00:00:00,000 --> 00:00:03,005 (dramatic music) (plane engine roars) 2 00:00:02,000 --> 00:00:07,000 Downloaded from YTS.MX 3 00:00:03,005 --> 00:00:04,680 (gunfire popping) (water splashes) 4 00:00:04,680 --> 00:00:07,870 - [Narrator] The outcome of World War II is at stake. 5 00:00:07,870 --> 00:00:11,020 Over 400 American and Japanese warships 6 00:00:08,000 --> 00:00:13,000 Official YIFY movies site: YTS.MX 7 00:00:11,020 --> 00:00:12,220 do battle at Leyte Gulf. 8 00:00:13,175 --> 00:00:16,269 - It was the largest naval action in history. 9 00:00:16,269 --> 00:00:17,590 (light music) 10 00:00:17,590 --> 00:00:19,800 - [Narrator] Japan is counting on a secret weapon 11 00:00:19,800 --> 00:00:22,233 the Americans know almost nothing about, 12 00:00:23,200 --> 00:00:26,430 except her name, Musashi. 13 00:00:26,430 --> 00:00:29,100 - You'll find, in the summer of 1944, 14 00:00:29,100 --> 00:00:32,210 the naval intelligence experts groping 15 00:00:32,210 --> 00:00:35,120 for an understanding of these huge ships. 16 00:00:35,120 --> 00:00:37,630 - [Narrator] At 72,000 tons, 17 00:00:37,630 --> 00:00:40,610 she's the largest battleship ever built. 18 00:00:40,610 --> 00:00:42,860 - She's not just 10% bigger than some 19 00:00:42,860 --> 00:00:45,870 of these other vessels, she's nearly double. 20 00:00:45,870 --> 00:00:48,770 - [Narrator] Bristling with anti-aircraft batteries 21 00:00:48,770 --> 00:00:51,037 and massive 18-inch guns. 22 00:00:51,037 --> 00:00:52,856 (guns banging) 23 00:00:52,856 --> 00:00:55,500 - You can't believe all the firepower 24 00:00:55,500 --> 00:00:57,563 that comes up at one time. 25 00:00:58,460 --> 00:01:01,487 - [Narrator] Her builders boast, "She's unsinkable." 26 00:01:02,610 --> 00:01:05,270 Yet, in her first major fight, 27 00:01:05,270 --> 00:01:09,170 this super battleship is sent crashing to the ocean floor. 28 00:01:09,170 --> 00:01:13,420 (water splashing) (metal creaks) 29 00:01:13,420 --> 00:01:16,422 But mysteries have always surrounded Musashi. 30 00:01:16,422 --> 00:01:18,210 (dramatic music) 31 00:01:18,210 --> 00:01:21,610 Now, Americans and Japanese researchers 32 00:01:21,610 --> 00:01:25,665 are joining forces to unlock her most stubborn secrets. 33 00:01:25,665 --> 00:01:27,955 (graphics whirring) 34 00:01:27,955 --> 00:01:29,880 (Hirotada speaks in foreign language) 35 00:01:29,880 --> 00:01:30,780 - [Interpreter] This front part 36 00:01:30,780 --> 00:01:32,863 is where flooding is taking place. 37 00:01:35,150 --> 00:01:39,563 - [Narrator] Why did an unsinkable giant go down so fast? 38 00:01:40,460 --> 00:01:42,830 Was it overwhelming American air power 39 00:01:43,890 --> 00:01:46,090 or a fatal design flaw that sent 40 00:01:46,090 --> 00:01:49,303 nearly 1,000 Japanese sailors to their death? 41 00:01:50,951 --> 00:01:52,240 (Masahiro speaks in foreign language) 42 00:01:52,240 --> 00:01:54,450 - [Interpreter] Hundreds of people are crying for help 43 00:01:54,450 --> 00:01:58,792 in horrified voices as they were all sucked into the waves. 44 00:01:58,792 --> 00:02:01,320 (plane engine roars) 45 00:02:01,320 --> 00:02:04,400 - [Narrator] To unravel the mysteries of Musashi, 46 00:02:04,400 --> 00:02:07,883 the missing giant must first be found. 47 00:02:09,602 --> 00:02:12,998 (water gurgling) 48 00:02:12,998 --> 00:02:15,609 (waves splash) 49 00:02:15,609 --> 00:02:18,020 (light music) 50 00:02:18,020 --> 00:02:21,630 In February 2011, a research vessel 51 00:02:21,630 --> 00:02:23,570 begins a three week expedition 52 00:02:23,570 --> 00:02:26,523 in the Sibuyan Sea of the Central Philippines. 53 00:02:28,100 --> 00:02:30,450 - You know, if this was anywhere else, 54 00:02:30,450 --> 00:02:32,690 all the coastline would have been changed 55 00:02:32,690 --> 00:02:35,010 with buildings and high-rises and all sorts of things. 56 00:02:35,010 --> 00:02:37,690 And that's not the case here, so we know we're looking at 57 00:02:37,690 --> 00:02:39,040 basically what the pilots 58 00:02:39,040 --> 00:02:43,600 saw 70 odd years ago. (flash bulb popping) 59 00:02:43,600 --> 00:02:45,430 - [Narrator] The expedition is the brainchild 60 00:02:45,430 --> 00:02:48,833 of the late Paul Allen, co-founder of Microsoft. 61 00:02:50,910 --> 00:02:53,210 The son of a World War II veteran, 62 00:02:53,210 --> 00:02:55,290 Allen committed significant resources 63 00:02:55,290 --> 00:02:58,593 to searching for the war's most iconic missing shipwrecks. 64 00:02:59,530 --> 00:03:02,033 Among them, the mysterious Musashi. 65 00:03:03,465 --> 00:03:05,810 (ship crew chattering) 66 00:03:05,810 --> 00:03:09,593 Rob Kraft is in charge of conducting all sub sea operations. 67 00:03:10,773 --> 00:03:12,240 (guns bang) 68 00:03:12,240 --> 00:03:14,510 - Musashi was the pride of the Japanese fleet. 69 00:03:14,510 --> 00:03:16,820 It was so important to the Japanese people 70 00:03:16,820 --> 00:03:19,131 that they didn't even inform the population 71 00:03:19,131 --> 00:03:20,413 that it has sunk. 72 00:03:20,413 --> 00:03:22,890 - Lots of people would like to find the Musashi. 73 00:03:22,890 --> 00:03:24,230 It's one of the great battleships, 74 00:03:24,230 --> 00:03:26,700 it's one of the truly remarkable ones 75 00:03:26,700 --> 00:03:28,031 that haven't been found. 76 00:03:28,031 --> 00:03:29,300 That is-- - I think there's something-- 77 00:03:29,300 --> 00:03:31,070 - [Narrator] David Mearns has made a career 78 00:03:31,070 --> 00:03:32,893 out of hunting for lost shipwrecks. 79 00:03:32,893 --> 00:03:35,160 (soft dramatic music) 80 00:03:35,160 --> 00:03:36,930 After months spent combing 81 00:03:36,930 --> 00:03:40,510 through military archives in the US and Japan-- 82 00:03:40,510 --> 00:03:42,170 - [David] And what it's showing you here. 83 00:03:42,170 --> 00:03:43,980 - [Narrator] He's identified the critical clues 84 00:03:43,980 --> 00:03:46,260 he hopes will lead them to Musashi. 85 00:03:46,260 --> 00:03:48,550 - The key is that one. 86 00:03:48,550 --> 00:03:49,922 - [Narrator] One is visual, 87 00:03:49,922 --> 00:03:51,130 (flash bulb pops) 88 00:03:51,130 --> 00:03:54,020 aerial photographs taken by American pilots 89 00:03:54,020 --> 00:03:55,993 during their final devastating attack. 90 00:03:55,993 --> 00:03:58,348 (flash bulb pops) 91 00:03:58,348 --> 00:04:01,020 - [David] There's the plane coming in lining up 92 00:04:01,020 --> 00:04:04,040 right there to attack Musashi 93 00:04:04,040 --> 00:04:06,616 and this is the next frame in the sequence. 94 00:04:06,616 --> 00:04:09,516 You can no longer see the plane, but we see a torpedo hit. 95 00:04:09,516 --> 00:04:11,470 (flash bulb pops) 96 00:04:11,470 --> 00:04:13,450 - [Narrator] Clearly recognizable in the background 97 00:04:13,450 --> 00:04:15,880 of these photographs, is the outline 98 00:04:15,880 --> 00:04:18,833 of Sibuyan Island a few miles to the south. 99 00:04:21,350 --> 00:04:22,450 - [Rob] Outside this circle? 100 00:04:22,450 --> 00:04:23,400 - [David] Outside the blue circle. 101 00:04:23,400 --> 00:04:24,233 - [Rob] Outside the blue. 102 00:04:24,233 --> 00:04:25,403 - [David] Yeah, yeah. 103 00:04:26,310 --> 00:04:27,840 - [Narrator] But there are other clues 104 00:04:27,840 --> 00:04:30,733 that may narrow down the search even further. 105 00:04:32,390 --> 00:04:34,590 - And the most important one came 106 00:04:34,590 --> 00:04:37,250 from one of the destroyers, the Japanese destroyer 107 00:04:37,250 --> 00:04:40,740 that was ordered to stand by Musashi. 108 00:04:40,740 --> 00:04:44,633 Kiyoshimo actually took a position for Musashi sinking. 109 00:04:45,830 --> 00:04:47,390 - [Narrator] Using the position reported 110 00:04:47,390 --> 00:04:49,460 by the destroyer, Kiyoshimo, 111 00:04:49,460 --> 00:04:51,180 Mearns and Kraft have determined 112 00:04:51,180 --> 00:04:53,143 a high-probability search area. 113 00:04:55,280 --> 00:04:57,320 The tool selected for the search 114 00:04:57,320 --> 00:05:00,370 is called a multibeam echosounder. 115 00:05:00,370 --> 00:05:03,373 It's a type of sonar that's mounted on a ship's hull. 116 00:05:04,330 --> 00:05:07,850 An array of downward-looking beams emitting sound waves 117 00:05:07,850 --> 00:05:09,550 sweeps across the seabed 118 00:05:09,550 --> 00:05:11,994 to create an image of a mile-wide swath. 119 00:05:11,994 --> 00:05:13,850 (soft dramatic music) (water gurgling) 120 00:05:13,850 --> 00:05:17,350 - We're over here on the western side of our box. 121 00:05:17,350 --> 00:05:20,070 We're running the first line to the east 122 00:05:20,070 --> 00:05:23,290 and this happens to be line number 13. 123 00:05:23,290 --> 00:05:26,273 And each line should take about four hours. 124 00:05:27,360 --> 00:05:28,820 - And because we're looking for, 125 00:05:28,820 --> 00:05:30,430 in the terms of the depth of the water, 126 00:05:30,430 --> 00:05:32,090 quite a small target. 127 00:05:32,090 --> 00:05:35,730 We're mapping the seabed in very, very high detail. 128 00:05:35,730 --> 00:05:39,560 So the byproduct of our search is a really detailed map 129 00:05:39,560 --> 00:05:41,763 of this particular part of the Philippines. 130 00:05:42,920 --> 00:05:44,860 - [Narrator] Even though Musashi is as big 131 00:05:44,860 --> 00:05:49,740 as a 75-story building, the battleship will only show up 132 00:05:49,740 --> 00:05:53,453 as a small speck on this vast and unexplored seafloor. 133 00:05:54,750 --> 00:05:57,053 There's no guarantee she can be found. 134 00:05:58,810 --> 00:06:00,910 - It all depends on her orientation on the bottom, 135 00:06:00,910 --> 00:06:04,040 if she's in one piece, two piece, three pieces. 136 00:06:04,040 --> 00:06:05,920 We should be able to detect that and see them 137 00:06:05,920 --> 00:06:08,000 in what they call the backscatter imagery. 138 00:06:08,000 --> 00:06:09,100 When you hit something hard, 139 00:06:09,100 --> 00:06:11,303 it shows up as a very, very dark object. 140 00:06:12,492 --> 00:06:14,909 (soft music) 141 00:06:16,190 --> 00:06:17,560 - [Narrator] It takes four days 142 00:06:17,560 --> 00:06:19,853 to cover the high-probability area. 143 00:06:22,110 --> 00:06:25,630 It yields an impressive picture of the seabed below, 144 00:06:25,630 --> 00:06:27,973 including a newly discovered seamount. 145 00:06:29,310 --> 00:06:32,573 But so far, there's no sign of Musashi. 146 00:06:33,520 --> 00:06:36,630 - So our highest probability to begin with 147 00:06:36,630 --> 00:06:40,540 was all on the basis of this Japanese destroyer, Kiyoshimo, 148 00:06:40,540 --> 00:06:43,210 which gave a precise sinking position. 149 00:06:43,210 --> 00:06:44,840 It's now very clear that 150 00:06:44,840 --> 00:06:48,220 that position wasn't as accurate as I had hoped. 151 00:06:48,220 --> 00:06:51,220 And the cost of that, we're now having to expand the search. 152 00:06:53,174 --> 00:06:54,840 (soft dramatic music) 153 00:06:54,840 --> 00:06:57,540 - [Narrator] Their focus shifts to the second, 154 00:06:57,540 --> 00:06:59,389 albeit less precise clue-- 155 00:06:59,389 --> 00:07:00,740 - That's the bow. 156 00:07:00,740 --> 00:07:02,280 - [Narrator] The aerial photographs taken 157 00:07:02,280 --> 00:07:04,843 by the American planes attacking Musashi. 158 00:07:05,810 --> 00:07:08,120 - I mean, I think if we go down here, 159 00:07:08,120 --> 00:07:09,880 we're gonna be able to, we're gonna be able 160 00:07:09,880 --> 00:07:10,820 to get a better feel. 161 00:07:10,820 --> 00:07:11,653 - [Rob] Yeah. 162 00:07:13,070 --> 00:07:14,870 - [Narrator] This cardboard box, 163 00:07:14,870 --> 00:07:16,550 which has the same field of view 164 00:07:16,550 --> 00:07:19,110 as the camera the airmen used, 165 00:07:19,110 --> 00:07:22,793 allows Mearns to get a close approximation of what they saw. 166 00:07:23,880 --> 00:07:26,340 - Musashi would be about two kilometers closer 167 00:07:26,340 --> 00:07:29,467 to the island from here when these photographs were taken. 168 00:07:29,467 --> 00:07:30,300 (flash bulb pops) 169 00:07:30,300 --> 00:07:32,693 And she sinks four hours later. 170 00:07:34,030 --> 00:07:36,810 - [Narrator] With the evidence gleaned from the photos, 171 00:07:36,810 --> 00:07:40,160 they plot a new series of sonar runs. 172 00:07:40,160 --> 00:07:42,620 - That's what we've covered, that red line there. 173 00:07:42,620 --> 00:07:45,170 Anywhere outside of that, she could be. 174 00:07:45,170 --> 00:07:47,920 - I would almost bias it further to the west, 175 00:07:47,920 --> 00:07:49,377 because in that photograph, 176 00:07:49,377 --> 00:07:50,210 (flash bulb pops) 177 00:07:50,210 --> 00:07:52,390 she's clearly heading westerly 178 00:07:52,390 --> 00:07:54,730 as opposed to north. (flash bulb pops) 179 00:07:54,730 --> 00:07:56,362 - [Narrator] But the clock is ticking. 180 00:07:56,362 --> 00:07:57,660 (flash bulb pops) 181 00:07:57,660 --> 00:07:59,745 The expedition only has two weeks left 182 00:07:59,745 --> 00:08:02,282 to find the mystery ship. 183 00:08:02,282 --> 00:08:04,700 (soft dramatic music) 184 00:08:04,700 --> 00:08:08,003 Musashi was first conceived in the 1930s, 185 00:08:08,003 --> 00:08:09,370 (gun popping) 186 00:08:09,370 --> 00:08:12,680 a time when Japan's efforts to expand it's territory 187 00:08:12,680 --> 00:08:15,960 and influence in Asia and the Pacific 188 00:08:15,960 --> 00:08:19,070 were increasingly blocked by it's former ally, 189 00:08:19,070 --> 00:08:20,393 the United States. 190 00:08:21,440 --> 00:08:25,330 - Japanese national prestige had been dealt an insult 191 00:08:25,330 --> 00:08:27,110 by the Washington Naval Treaty. 192 00:08:27,110 --> 00:08:28,260 Just to put it in numbers, 193 00:08:28,260 --> 00:08:30,770 the treaty created circumstances where 194 00:08:30,770 --> 00:08:33,960 for every 100 United States warships that are built, 195 00:08:33,960 --> 00:08:36,550 the Japanese are permitted 60. 196 00:08:36,550 --> 00:08:38,850 It created a future in which the Japanese Imperial Navy 197 00:08:38,850 --> 00:08:41,180 was going to be numerically inferior 198 00:08:41,180 --> 00:08:42,623 to the United States Navy. 199 00:08:44,250 --> 00:08:46,730 - [Narrator] In response, a powerful faction 200 00:08:46,730 --> 00:08:49,563 begins advocating for a different strategy. 201 00:08:50,642 --> 00:08:53,750 (Toshiya speaks in foreign language) 202 00:08:53,750 --> 00:08:54,790 - [Interpreter] Japan, at the time, 203 00:08:54,790 --> 00:08:56,728 had neither the resources nor the budget 204 00:08:56,728 --> 00:08:58,990 to build a large number of battleships 205 00:08:58,990 --> 00:09:00,463 to fight against the US. 206 00:09:03,370 --> 00:09:05,820 So they decided to counter quantity with quality. 207 00:09:07,690 --> 00:09:09,490 That was the idea they came up with. 208 00:09:10,510 --> 00:09:13,740 - [Narrator] Quality meant constructing giant battleships 209 00:09:13,740 --> 00:09:16,673 that could overcome the enemy's larger numbers. 210 00:09:18,150 --> 00:09:21,140 The new battleship was called the Yamato-class 211 00:09:21,140 --> 00:09:22,643 after it's prototype. 212 00:09:23,890 --> 00:09:27,440 To win public support, this navy handbook likens it 213 00:09:27,440 --> 00:09:30,962 to a powerful figure in a popular movie of the time. 214 00:09:30,962 --> 00:09:33,712 (sinister music) 215 00:09:37,370 --> 00:09:39,410 (crowd screaming) 216 00:09:39,410 --> 00:09:42,810 The Hollywood film about a giant ape creating mayhem 217 00:09:42,810 --> 00:09:46,662 in New York was a huge hit with Japanese audiences. 218 00:09:46,662 --> 00:09:48,700 (woman screaming) 219 00:09:48,700 --> 00:09:51,930 - And so the comparison is not just a comparison 220 00:09:51,930 --> 00:09:54,350 evocative of power and strength, 221 00:09:54,350 --> 00:09:57,680 it's also kind of pointed squarely at New York City, 222 00:09:57,680 --> 00:10:00,544 and, therefore, pointed directly at the Americans. 223 00:10:00,544 --> 00:10:03,660 (soft music) (film whirs) 224 00:10:03,660 --> 00:10:07,250 - [Narrator] In March 1938, construction of Musashi 225 00:10:07,250 --> 00:10:11,243 began here at the Mitsubishi Shipyard in Nagasaki. 226 00:10:14,060 --> 00:10:17,470 Incredibly, the giant gantry crane that built her 227 00:10:17,470 --> 00:10:19,123 is still in use today. 228 00:10:21,560 --> 00:10:24,100 - The Japanese virtually had to reinvent 229 00:10:24,100 --> 00:10:26,700 naval architecture and design of ships 230 00:10:26,700 --> 00:10:29,143 to be able to build such colossal vessels. 231 00:10:30,730 --> 00:10:34,363 - [Narrator] Work proceeded under a literal veil of secrecy. 232 00:10:35,660 --> 00:10:37,500 - When they were being built, they were actually built 233 00:10:37,500 --> 00:10:39,120 behind gigantic curtains 234 00:10:39,120 --> 00:10:40,410 that were raised up in the shipyards. 235 00:10:40,410 --> 00:10:42,740 And so even friendly people couldn't see 236 00:10:42,740 --> 00:10:43,930 what was going on behind there. 237 00:10:43,930 --> 00:10:46,230 So there was some attempt to keep it a secret. 238 00:10:47,860 --> 00:10:49,700 - A schoolgirl at the time, 239 00:10:49,700 --> 00:10:52,253 Ms. Matsuura remember what it was like. 240 00:10:53,876 --> 00:10:55,010 (Sachie speaks in foreign language) 241 00:10:55,010 --> 00:10:56,330 - [Interpreter] I was told never to look 242 00:10:56,330 --> 00:10:58,350 in the direction of the shipyard, 243 00:10:58,350 --> 00:11:01,077 that soldiers are onboard keeping watch, 244 00:11:01,077 --> 00:11:05,030 "You must not look or the soldiers will take you away." 245 00:11:05,030 --> 00:11:06,960 Even as a child, I kind of sensed 246 00:11:06,960 --> 00:11:09,103 that a big war was going to break out. 247 00:11:09,946 --> 00:11:11,110 (dramatic music) 248 00:11:11,110 --> 00:11:16,110 - [Narrator] On December 7th, 1941, that war began. 249 00:11:16,180 --> 00:11:19,150 In it's surprise attack on Pearl Harbor, 250 00:11:19,150 --> 00:11:22,340 the Japanese Navy used carrier-based air power 251 00:11:22,340 --> 00:11:25,283 to devastating effect against the American fleet. 252 00:11:26,490 --> 00:11:30,450 Ironically, that success only reinforced it's faith 253 00:11:30,450 --> 00:11:33,023 in it's own new super battleships. 254 00:11:34,110 --> 00:11:36,040 - A lot of the naval theory at the time 255 00:11:36,040 --> 00:11:38,540 was based on this fleet-on-fleet engagement. 256 00:11:38,540 --> 00:11:40,390 The Japanese, in particular, were still hoping 257 00:11:40,390 --> 00:11:42,160 for that kind of thing. 258 00:11:42,160 --> 00:11:44,880 This is how you arrest sea control from the other guy, 259 00:11:44,880 --> 00:11:46,193 you defeat his fleet. 260 00:11:47,500 --> 00:11:48,880 (guns bang) 261 00:11:48,880 --> 00:11:53,020 - [Narrator] In August 1942, Musashi began 262 00:11:53,020 --> 00:11:54,990 secret sea trials. 263 00:11:54,990 --> 00:11:58,320 Weapons and defenses carefully kept out of sight 264 00:11:58,320 --> 00:12:01,253 from enemy spies were put to the test. 265 00:12:02,779 --> 00:12:04,950 - Mushashi's main armament came in the form 266 00:12:04,950 --> 00:12:09,950 of three turrets mounting three Type 94 naval guns. 267 00:12:10,060 --> 00:12:12,070 These were of 18-inch caliber, 268 00:12:12,070 --> 00:12:15,500 and were therefore the largest naval guns in use 269 00:12:15,500 --> 00:12:16,997 anywhere in the world. 270 00:12:16,997 --> 00:12:19,580 (guns banging) 271 00:12:22,550 --> 00:12:25,280 - [Narrator] To defend herself, Musashi was shielded 272 00:12:25,280 --> 00:12:29,370 by the heaviest armor ever used on a ships hull. 273 00:12:29,370 --> 00:12:32,900 The high-grade steel came from low-phosphorous iron 274 00:12:32,900 --> 00:12:36,513 secretly mined in Japanese occupied Manchuria. 275 00:12:38,070 --> 00:12:41,040 For 19-year-old Masahiro Ohishi 276 00:12:41,040 --> 00:12:42,790 and the hundreds of young sailors 277 00:12:42,790 --> 00:12:45,520 assigned to serve aboard this giant, 278 00:12:45,520 --> 00:12:49,174 Musashi was a technological wonder. 279 00:12:49,174 --> 00:12:53,120 (Masahiro speaks in foreign language) 280 00:12:53,120 --> 00:12:54,950 - [Interpreter] We never thought for a second 281 00:12:54,950 --> 00:12:58,280 that Musashi would sink and people would die. 282 00:12:58,280 --> 00:13:01,894 We believed that such a giant ship could not be taken down. 283 00:13:01,894 --> 00:13:03,920 (soft music) 284 00:13:03,920 --> 00:13:07,373 - [Narrator] To them, she was the King Kong of the sea. 285 00:13:11,448 --> 00:13:13,350 (dramatic music) 286 00:13:13,350 --> 00:13:16,140 Day 14 of the Musashi search expedition. 287 00:13:16,140 --> 00:13:18,280 - Five, in this direction here. 288 00:13:18,280 --> 00:13:20,110 - [Narrator] At last, the team thinks 289 00:13:20,110 --> 00:13:21,263 they're onto something. 290 00:13:22,431 --> 00:13:26,387 - [Man] It should be broken in four pieces sitting there. 291 00:13:26,387 --> 00:13:28,660 - [Narrator] One of their sonar runs 292 00:13:28,660 --> 00:13:31,528 has revealed a promising target. 293 00:13:31,528 --> 00:13:33,780 - [David] That is exactly what you wanna look for, 294 00:13:33,780 --> 00:13:37,652 bow, superstructure, things falling off the superstructure, 295 00:13:37,652 --> 00:13:40,840 blah, blah, blah, central area, engine room, 296 00:13:40,840 --> 00:13:43,261 break here, explosion there, stern. 297 00:13:43,261 --> 00:13:45,300 It's all gonna be right there. 298 00:13:45,300 --> 00:13:48,253 And if it capsized, it's gonna be over. 299 00:13:50,810 --> 00:13:53,950 - [Narrator] But after making several more sonar runs, 300 00:13:53,950 --> 00:13:56,690 they reluctantly reach the conclusion, 301 00:13:56,690 --> 00:13:58,773 the object is too large. 302 00:13:59,990 --> 00:14:01,530 - [David] You know, it's 100 meters bigger 303 00:14:01,530 --> 00:14:05,183 than what we're looking for, so it's 30% bigger. 304 00:14:05,183 --> 00:14:07,190 - [Rob] I think it's definitely something 305 00:14:08,180 --> 00:14:11,685 other than geology, but I don't think it's Musashi. 306 00:14:11,685 --> 00:14:14,185 (light music) 307 00:14:16,680 --> 00:14:17,990 - [Narrator] After three weeks, 308 00:14:17,990 --> 00:14:20,580 the expedition is out of time. 309 00:14:20,580 --> 00:14:23,197 The research vessel must return to port. 310 00:14:23,197 --> 00:14:27,221 But they've covered a staggering 1,400 square miles, 311 00:14:27,221 --> 00:14:30,740 an area as big as the state of Rhode Island. 312 00:14:30,740 --> 00:14:33,566 - What we now have is a very highly accurate map 313 00:14:33,566 --> 00:14:37,020 of the entire area that we want to search. 314 00:14:37,020 --> 00:14:38,810 We know where she's not, we've ruled out 315 00:14:38,810 --> 00:14:40,763 large swaths of the Sibuyan Sea. 316 00:14:41,640 --> 00:14:43,960 - [Narrator] And their commitment to the task 317 00:14:43,960 --> 00:14:46,290 has only intensified. 318 00:14:46,290 --> 00:14:48,340 - Everybody's kinda got a lot of blood, sweat and tears 319 00:14:48,340 --> 00:14:50,580 in trying to find this wreck. 320 00:14:50,580 --> 00:14:52,510 You know, you get this personal passion going 321 00:14:52,510 --> 00:14:54,381 trying to find this thing. 322 00:14:54,381 --> 00:14:56,320 (dramatic music) 323 00:14:56,320 --> 00:14:59,090 - [Narrator] But to succeed, they must first find 324 00:14:59,090 --> 00:15:02,877 a better tool for searching the rugged sea floor below. 325 00:15:02,877 --> 00:15:04,401 (water splashing) 326 00:15:04,401 --> 00:15:07,150 (dramatic music) 327 00:15:07,150 --> 00:15:10,270 By the time Musashi joined the Japanese war effort 328 00:15:10,270 --> 00:15:15,270 in the Pacific in 1942, the momentum was about to shift. 329 00:15:16,370 --> 00:15:18,160 - The Japanese, actually, are prevailing at this point, 330 00:15:18,160 --> 00:15:20,350 'cause they're better at surface warfare than we are 331 00:15:20,350 --> 00:15:22,300 at this early stage in the game. 332 00:15:22,300 --> 00:15:23,350 What then becomes clear 333 00:15:23,350 --> 00:15:26,350 is that anytime aircraft carriers get involved, 334 00:15:26,350 --> 00:15:28,300 the whole thing changes. 335 00:15:28,300 --> 00:15:30,230 - The US embraces naval airpower 336 00:15:30,230 --> 00:15:31,911 in a way that it just hadn't before. 337 00:15:31,911 --> 00:15:36,080 It revises the way that it trains, revises tactics 338 00:15:36,080 --> 00:15:38,280 and it revises weapons to the extent 339 00:15:38,280 --> 00:15:40,350 that it introduces a new fighter, 340 00:15:40,350 --> 00:15:42,990 a new dive bomber, a new torpedo bomber, 341 00:15:42,990 --> 00:15:45,993 and it even introduces a new torpedo. 342 00:15:46,860 --> 00:15:50,340 - [Narrator] The Mark 13 torpedo was more reliable 343 00:15:50,340 --> 00:15:52,140 and could be dropped at higher altitude 344 00:15:52,140 --> 00:15:53,353 than it's predecessor. 345 00:15:55,780 --> 00:15:58,960 At the same time, American intelligence 346 00:15:58,960 --> 00:16:01,490 secured a valuable lead. 347 00:16:01,490 --> 00:16:04,772 - On the island of Tulagi, Americans captured a document 348 00:16:04,772 --> 00:16:09,010 that was a warship recognition manual 349 00:16:09,010 --> 00:16:11,770 that was to be used by Imperial Navy sailors 350 00:16:11,770 --> 00:16:13,540 to recognize their own ships. 351 00:16:13,540 --> 00:16:17,543 And it had a drawing of a Yamato-class ship. 352 00:16:19,060 --> 00:16:21,313 - [Narrator] But after that, nothing. 353 00:16:22,680 --> 00:16:27,570 It's as if Japan's most secret weapon had vanished. 354 00:16:27,570 --> 00:16:30,350 - You'll find in the summer of 1944, 355 00:16:30,350 --> 00:16:33,550 the naval intelligence experts groping 356 00:16:33,550 --> 00:16:36,201 for an understanding of these huge ships 357 00:16:36,201 --> 00:16:41,201 and they came up with estimates that were just unbelievable. 358 00:16:42,180 --> 00:16:44,140 - [Narrator] But as they would later discover, 359 00:16:44,140 --> 00:16:48,001 even those estimates were way too small. 360 00:16:48,001 --> 00:16:50,090 (dramatic music) 361 00:16:50,090 --> 00:16:54,290 By June 1944, American forces succeeded 362 00:16:54,290 --> 00:16:56,590 in pushing the Japanese fleet, 363 00:16:56,590 --> 00:17:00,280 totalling some 60 ships and 450 aircraft, 364 00:17:00,280 --> 00:17:02,240 out of the Western Pacific. 365 00:17:02,240 --> 00:17:07,120 The battle became known as the Great Marianas Turkey Shoot. 366 00:17:07,120 --> 00:17:09,710 - They call it that because they harvest 367 00:17:09,710 --> 00:17:11,710 so many Japanese aircraft. 368 00:17:11,710 --> 00:17:14,420 They shoot them down wholesale. 369 00:17:14,420 --> 00:17:16,800 The Japanese lose half their carrier strength 370 00:17:16,800 --> 00:17:21,303 and they lose almost all of their naval aviation. 371 00:17:22,390 --> 00:17:24,810 - [Narrator] American general Douglas MacArthur 372 00:17:24,810 --> 00:17:27,280 was now poised to invade the gateway 373 00:17:27,280 --> 00:17:30,563 to Japan itself, the Philippines. 374 00:17:32,936 --> 00:17:36,260 On October 20th, MacArthur came ashore 375 00:17:36,260 --> 00:17:39,530 on the eastern side of Leyte Island, 376 00:17:39,530 --> 00:17:42,643 where American troops encountered little resistance. 377 00:17:43,950 --> 00:17:48,950 - The opinion, united, of American intelligence agencies 378 00:17:48,990 --> 00:17:51,930 was that the Japanese Navy would not come out. 379 00:17:51,930 --> 00:17:55,180 We based our ideas on the assumption 380 00:17:55,180 --> 00:17:58,220 that the Japanese would need a considerable amount of time 381 00:17:58,220 --> 00:18:01,220 to train new aircrew and pilots 382 00:18:01,220 --> 00:18:03,253 for their aircraft carrier groups. 383 00:18:05,150 --> 00:18:07,440 - [Narrator] But American intelligence was ignoring 384 00:18:07,440 --> 00:18:11,910 one critical fact: Japan's Navy remained committed 385 00:18:11,910 --> 00:18:14,573 to fighting a decisive battle at sea. 386 00:18:15,510 --> 00:18:18,780 It's surface fleet was still largely intact, 387 00:18:18,780 --> 00:18:22,483 led by two giants Americans had yet to lay eyes on, 388 00:18:23,340 --> 00:18:25,363 Musashi and Yamato. 389 00:18:26,200 --> 00:18:28,970 - American radio intelligence had knowledge 390 00:18:28,970 --> 00:18:31,392 of the movements of these Japanese ships, 391 00:18:31,392 --> 00:18:35,920 but still not of their characteristics. 392 00:18:35,920 --> 00:18:39,050 - [Narrator] On October 24th, 1944, 393 00:18:39,050 --> 00:18:42,600 Admiral Kurita's Center Force, with 26 ships, 394 00:18:42,600 --> 00:18:44,273 entered the Sibuyan Sea. 395 00:18:45,570 --> 00:18:48,220 Two other slightly smaller Japanese fleets 396 00:18:48,220 --> 00:18:50,343 approached from the south and north. 397 00:18:51,740 --> 00:18:54,964 The Battle of Leyte Gulf was about to begin. 398 00:18:54,964 --> 00:18:58,280 (soft dramatic music) 399 00:18:58,280 --> 00:19:01,960 - In the morning, when Kurita is crossing the Sibuyan Sea, 400 00:19:01,960 --> 00:19:03,890 the reconnaissance flights picked this up, 401 00:19:03,890 --> 00:19:05,430 and, of course, at that point, they're aware 402 00:19:05,430 --> 00:19:08,810 they got two very large battleships down here. 403 00:19:08,810 --> 00:19:10,585 - [Narrator] American Pilots were the first 404 00:19:10,585 --> 00:19:14,663 to catch a real glimpse of Musashi and Yamato. 405 00:19:15,540 --> 00:19:18,327 - We knew that they had two big battleships, 406 00:19:18,327 --> 00:19:19,893 and that's about all we knew. 407 00:19:21,020 --> 00:19:23,833 And it was, obviously, the biggest thing we'd ever seen. 408 00:19:24,900 --> 00:19:27,020 - [Narrator] Although caught by surprise, 409 00:19:27,020 --> 00:19:29,770 the US Navy was prepared. 410 00:19:29,770 --> 00:19:33,680 7th Fleet moved to guard the Leyte landing site itself, 411 00:19:33,680 --> 00:19:37,263 while 3rd Fleet deployed in three groups to the north. 412 00:19:38,220 --> 00:19:40,520 - Unfortunately, the one element of the 3rd Fleet 413 00:19:40,520 --> 00:19:42,256 that's closest to San Bernardino Strait 414 00:19:42,256 --> 00:19:44,370 is a little bit weaker because it sent 415 00:19:44,370 --> 00:19:46,413 one of it's carriers off to refuel. 416 00:19:47,430 --> 00:19:50,831 It's sole remaining large carrier was only half the size 417 00:19:50,831 --> 00:19:54,240 of the two giants bearing down on it 418 00:19:54,240 --> 00:19:58,393 with 24 more warships in Japan's Center Force. 419 00:19:59,957 --> 00:20:02,705 (soft dramatic music) 420 00:20:02,705 --> 00:20:05,610 (man speaking faintly on radio) 421 00:20:05,610 --> 00:20:08,460 - [Narrator] In late February 2015, 422 00:20:08,460 --> 00:20:12,533 Rob Kraft and David Mearns renew their search for Musashi. 423 00:20:14,290 --> 00:20:15,970 Since they were last here, 424 00:20:15,970 --> 00:20:19,373 they've found the perfect tool for the difficult task ahead. 425 00:20:22,410 --> 00:20:25,803 It's now installed aboard the expedition yacht, Octopus, 426 00:20:27,090 --> 00:20:30,053 equipped with state-of-the-art deep sea equipment. 427 00:20:32,720 --> 00:20:35,910 Their key search tool is still so new, 428 00:20:35,910 --> 00:20:39,104 it's rarely been used in the deep ocean. 429 00:20:39,104 --> 00:20:40,370 (machine whirs) 430 00:20:40,370 --> 00:20:43,790 - AUV is an autonomous underwater vehicle. 431 00:20:43,790 --> 00:20:48,163 Our AUV is capable of diving down to 1,500 meters. 432 00:20:49,280 --> 00:20:51,930 It takes with it a side scan sonar system 433 00:20:51,930 --> 00:20:56,450 that looks out on the sides and provides us an image 434 00:20:56,450 --> 00:20:58,683 of things that may be lying on he seafloor. 435 00:20:59,980 --> 00:21:02,420 - [Narrator] It's survey route is selected based on 436 00:21:02,420 --> 00:21:05,950 the bathymetric map that system engineer Wayne Szydtowski 437 00:21:05,950 --> 00:21:09,103 compiled during the 2011 expedition. 438 00:21:10,400 --> 00:21:13,340 - This map is of the, basically, of the sub sea volcano 439 00:21:13,340 --> 00:21:14,280 that we're seeing. 440 00:21:14,280 --> 00:21:15,740 And so, using this map, 441 00:21:15,740 --> 00:21:18,103 we then program the autonomous vehicle. 442 00:21:19,382 --> 00:21:21,960 - [Narrator] Traveling 2/3 of a mile down 443 00:21:21,960 --> 00:21:24,910 and a few hundred feet above the ocean floor, 444 00:21:24,910 --> 00:21:27,023 the AUV maps the terrain. 445 00:21:28,060 --> 00:21:30,170 But distinguishing a man-made object 446 00:21:30,170 --> 00:21:33,780 among the rugged volcanic outcrops is challenging. 447 00:21:33,780 --> 00:21:35,810 - Because a lava rock is as reflective 448 00:21:35,810 --> 00:21:37,810 as the acoustic waves are that we use 449 00:21:37,810 --> 00:21:40,073 to bounce off the metal of the Musashi. 450 00:21:41,880 --> 00:21:45,410 - [Narrator] After 18 hours, the AUV returns to the surface 451 00:21:45,410 --> 00:21:47,923 and is brought onboard to download the data. 452 00:21:49,680 --> 00:21:53,250 - Everybody had a go at looking at this HYSCAN information. 453 00:21:53,250 --> 00:21:54,770 Everybody, what do you see? 454 00:21:54,770 --> 00:21:55,810 Oh, that's something shiny there. 455 00:21:55,810 --> 00:21:57,540 That's a rock, no that's a rock. 456 00:21:57,540 --> 00:21:58,710 No, that's something. 457 00:21:58,710 --> 00:21:59,610 No, that's a rock. 458 00:22:00,500 --> 00:22:03,263 - [Narrator] The first AUV survey yields nothing, 459 00:22:04,760 --> 00:22:05,923 as does the second. 460 00:22:07,080 --> 00:22:09,360 - And I'll tell you that, up to that point, 461 00:22:09,360 --> 00:22:11,970 we were starting to second-guess ourselves. 462 00:22:11,970 --> 00:22:16,340 We had searched a large portion of the primary search area. 463 00:22:16,340 --> 00:22:19,453 And we weren't finding what we had hoped to find. 464 00:22:22,070 --> 00:22:25,972 - [Narrator] On the third run, they finally see something. 465 00:22:25,972 --> 00:22:28,410 (water gurgling) 466 00:22:28,410 --> 00:22:30,580 - Generally, when you're finding a wreck, 467 00:22:30,580 --> 00:22:33,110 it's either happening instantaneously, 468 00:22:33,110 --> 00:22:35,650 but, in this one, it was a bit of a slow burner, 469 00:22:35,650 --> 00:22:38,767 because there sonar image didn't sort of shout out, 470 00:22:38,767 --> 00:22:40,990 "This is Musashi, this is where I sank." 471 00:22:40,990 --> 00:22:44,300 it was more of there was an indication something was there. 472 00:22:44,300 --> 00:22:46,194 - [Man] David, buoy in the water. 473 00:22:46,194 --> 00:22:47,354 That's a safe heading 474 00:22:47,354 --> 00:22:49,150 Better wench that one up. 475 00:22:49,150 --> 00:22:51,120 - [Narrator] For a closer look, they launch 476 00:22:51,120 --> 00:22:53,713 a remotely operated vehicle, or ROV. 477 00:22:54,900 --> 00:22:57,050 - It's smaller than a Volkswagen Bug, 478 00:22:57,050 --> 00:22:59,020 but it's still quite substantial. 479 00:22:59,020 --> 00:23:01,530 And it's on a cable as well, but in that cable 480 00:23:01,530 --> 00:23:04,062 it has power conductors and fiber, 481 00:23:04,062 --> 00:23:05,930 and through that, we get to watch 482 00:23:05,930 --> 00:23:08,483 our HD camera that's on the end of a tether. 483 00:23:09,830 --> 00:23:11,550 - [Narrator] It will take the ROV an hour 484 00:23:11,550 --> 00:23:15,083 to reach the ocean floor almost a mile below, 485 00:23:17,110 --> 00:23:20,050 plenty of time to wonder if, at last, 486 00:23:20,050 --> 00:23:22,694 they're going to set eyes on Musashi. 487 00:23:22,694 --> 00:23:25,840 (dramatic music) 488 00:23:25,840 --> 00:23:29,800 On the morning of October 24th, 1944, 489 00:23:29,800 --> 00:23:32,320 the skies over the Sibuyan Sea were filled 490 00:23:32,320 --> 00:23:34,713 with over 40 American warplanes. 491 00:23:36,680 --> 00:23:40,330 - US Naval aircraft that opposed the Japanese Center Force 492 00:23:40,330 --> 00:23:44,367 in the Sibuyan Sea consists of the Hellcat fighter, 493 00:23:44,367 --> 00:23:49,350 the Helldiver dive bomber, and the Avenger torpedo bomber. 494 00:23:49,350 --> 00:23:52,390 - [Narrator] The fighters led the way with strafing runs. 495 00:23:52,390 --> 00:23:53,850 - You're gonna go after the battleships 496 00:23:53,850 --> 00:23:56,220 because they are the biggest target. 497 00:23:56,220 --> 00:23:57,700 They can do the most damage to you, 498 00:23:57,700 --> 00:23:59,800 and, therefore, you want to take them out. 499 00:24:00,710 --> 00:24:02,916 - [Narrator] But the Japanese gunners were ready, 500 00:24:02,916 --> 00:24:04,800 (plane engines roars) 501 00:24:04,800 --> 00:24:06,310 unleashing a hail of fire 502 00:24:06,310 --> 00:24:09,543 from Mushashi's 100 anti-aircraft guns. 503 00:24:10,746 --> 00:24:13,329 (guns banging) 504 00:24:18,730 --> 00:24:20,310 (Akio speaks in foreign language) 505 00:24:20,310 --> 00:24:22,710 - [Interpreter] Aerial attacks had become fierce 506 00:24:22,710 --> 00:24:24,600 after war broke out. 507 00:24:24,600 --> 00:24:26,050 So the decision was made 508 00:24:26,050 --> 00:24:28,660 to strengthen anti-aircraft defenses, 509 00:24:28,660 --> 00:24:32,080 and machine guns were also rapidly added. 510 00:24:32,080 --> 00:24:34,270 But there was no industrial capacity 511 00:24:34,270 --> 00:24:37,253 to manufacture bullet-proof armor at this point. 512 00:24:39,100 --> 00:24:40,790 - [Narrator] With little to protect them, 513 00:24:40,790 --> 00:24:43,743 some of the gun crews suffered heavy casualties. 514 00:24:44,986 --> 00:24:48,510 (Yoshiaki speaks in foreign language) 515 00:24:48,510 --> 00:24:50,860 - [Interpreter] Everything was blown to bits. 516 00:24:50,860 --> 00:24:53,360 There were pieces of machine gun everywhere 517 00:24:53,360 --> 00:24:55,740 with human flesh stuck to them. 518 00:24:55,740 --> 00:24:58,590 I could not believe that they were parts of human beings. 519 00:25:00,140 --> 00:25:02,850 - [Narrator] Bob Freligh was a 22-year-old pilot 520 00:25:02,850 --> 00:25:05,603 flying an Avenger torpedo bomber that day. 521 00:25:06,570 --> 00:25:09,660 - The sky is so big up there, I don't see all the fighters. 522 00:25:09,660 --> 00:25:12,500 I don't have time to look around to see anybody else 523 00:25:12,500 --> 00:25:14,533 because everything happens like that. 524 00:25:15,710 --> 00:25:19,683 - [Narrator] What he did see was a giant battleships below. 525 00:25:20,570 --> 00:25:24,300 - The Musashi has 11 planes coming in on it. 526 00:25:24,300 --> 00:25:27,900 You're coming down and you start leveling off. 527 00:25:27,900 --> 00:25:29,980 And all this time, they're shooting at you 528 00:25:29,980 --> 00:25:32,830 and you don't know whether this bullets gonna hit you or. 529 00:25:34,240 --> 00:25:38,310 So you get about the distance that you think you should be, 530 00:25:38,310 --> 00:25:42,250 at the altitude you should be, open your bomb bay doors, 531 00:25:42,250 --> 00:25:43,812 and you're all set, boom. 532 00:25:43,812 --> 00:25:45,090 (plane engine roars) 533 00:25:45,090 --> 00:25:46,700 - [Narrator] His rear gunner watched 534 00:25:46,700 --> 00:25:49,360 as their 2,000 pound torpedo slammed 535 00:25:49,360 --> 00:25:51,289 into Mushashi's port side. 536 00:25:51,289 --> 00:25:52,810 (torpedo bangs) 537 00:25:52,810 --> 00:25:55,460 - The torpedo bomber is the most effective weapon 538 00:25:55,460 --> 00:25:58,280 against a battleships because it can release something 539 00:25:58,280 --> 00:26:00,230 that carries a great deal of punch. 540 00:26:00,230 --> 00:26:02,810 The American Mark 13 torpedo carried a warhead 541 00:26:02,810 --> 00:26:05,040 of 600 pounds of high explosive. 542 00:26:05,040 --> 00:26:09,247 That was enough force to punch through an armor belt. 543 00:26:09,247 --> 00:26:11,130 (dramatic music) 544 00:26:11,130 --> 00:26:12,980 - [Narrator] Musashi withstood the initial 545 00:26:12,980 --> 00:26:16,613 American assault, but the attacks kept coming. 546 00:26:16,613 --> 00:26:19,970 (torpedoes banging) 547 00:26:19,970 --> 00:26:22,200 - The fleets that are there at Leyte 548 00:26:22,200 --> 00:26:25,030 consist of multiple aircraft carriers. 549 00:26:25,030 --> 00:26:26,960 It's mind-boggling by today's standards 550 00:26:26,960 --> 00:26:28,550 how many ships were there. 551 00:26:28,550 --> 00:26:30,530 And so, as a result of that, they can continue 552 00:26:30,530 --> 00:26:33,683 to attack and attack, and wave after wave coming in. 553 00:26:34,928 --> 00:26:37,220 (torpedo bangs) 554 00:26:37,220 --> 00:26:40,070 - [Narrator] During the last wave, an American pilot 555 00:26:40,070 --> 00:26:42,464 took his memorable series of photographs. 556 00:26:42,464 --> 00:26:45,464 (flash bulb popping) 557 00:26:45,464 --> 00:26:47,220 (plane engines roar) 558 00:26:47,220 --> 00:26:51,170 - [Narrator] The relentless onslaught began to take a toll. 559 00:26:51,170 --> 00:26:55,110 - When the Musashi loses speed and falls behind, 560 00:26:55,110 --> 00:26:58,523 then it's obvious that she's damaged, 561 00:26:59,660 --> 00:27:03,693 so now's the moment to close in for the kill. 562 00:27:03,693 --> 00:27:05,500 (soft dramatic music) 563 00:27:05,500 --> 00:27:07,464 - [Narrator] Lionel Gilbow was the rear gunner 564 00:27:07,464 --> 00:27:08,724 in a Helldiver bomber. 565 00:27:08,724 --> 00:27:10,260 (plane whooshes) 566 00:27:10,260 --> 00:27:13,030 - I probably dived-bombed a battleship 567 00:27:13,030 --> 00:27:16,070 with a 2,000 pound armor piercing bomb, 568 00:27:16,070 --> 00:27:17,393 right down the stack. 569 00:27:18,470 --> 00:27:21,440 (torpedo bangs) 570 00:27:21,440 --> 00:27:24,300 - These particular ships are very formidable ships, 571 00:27:24,300 --> 00:27:26,410 but they also made very large targets 572 00:27:26,410 --> 00:27:27,810 that were easily identified. 573 00:27:27,810 --> 00:27:29,040 And I think that's one of the reasons 574 00:27:29,040 --> 00:27:32,310 a lot of the aviators concentrated on Musashi, 575 00:27:32,310 --> 00:27:34,163 and she paid the price as a result. 576 00:27:35,510 --> 00:27:38,130 - [Narrator] Yamato escaped the onslaught, 577 00:27:38,130 --> 00:27:43,053 but at 7:39 p.m., four hours after the final attack, 578 00:27:44,440 --> 00:27:49,210 Musashi, crippled, yet miraculously still in one piece, 579 00:27:49,210 --> 00:27:51,072 rolled over and sank. 580 00:27:51,072 --> 00:27:52,876 (propellers whirring) 581 00:27:52,876 --> 00:27:55,730 (Masahiro speaks in foreign language) 582 00:27:55,730 --> 00:27:57,920 - [Interpreter] Hundreds of people are crying for help 583 00:27:57,920 --> 00:28:01,453 in horrified voices, as they were all sucked into the waves. 584 00:28:02,514 --> 00:28:05,347 (water splashing) 585 00:28:09,869 --> 00:28:12,633 (metal creaks) 586 00:28:12,633 --> 00:28:15,050 (soft music) 587 00:28:17,180 --> 00:28:20,090 - [Narrator] In the pitch darkness of the deep sea, 588 00:28:20,090 --> 00:28:24,100 the ROV pilot carefully maneuvers his vehicle. 589 00:28:24,100 --> 00:28:27,510 - We came across some very small pieces of debris 590 00:28:27,510 --> 00:28:30,520 which looked the right age, looked the right material. 591 00:28:30,520 --> 00:28:32,580 But we weren't quite certain. 592 00:28:32,580 --> 00:28:35,130 - Everybody was pretty much running on adrenalin 593 00:28:35,130 --> 00:28:36,200 at that time. 594 00:28:36,200 --> 00:28:38,033 It was very exciting. 595 00:28:39,120 --> 00:28:40,910 - [Narrator] The ROV moves slowly 596 00:28:40,910 --> 00:28:43,133 through this unfamiliar landscape. 597 00:28:44,819 --> 00:28:47,650 - It took about, I guess, a half hour or 45 minutes 598 00:28:47,650 --> 00:28:50,230 before we started getting into the heavier debris. 599 00:28:50,230 --> 00:28:53,506 And then it became more and more obvious. 600 00:28:53,506 --> 00:28:55,100 - [Man] Look, you see them, right? 601 00:28:55,100 --> 00:28:57,950 There's three characters over there, I think. 602 00:28:57,950 --> 00:29:01,253 - [Man] That's Japanese, it's a Japanese warship. 603 00:29:02,300 --> 00:29:03,583 - The minute we found the valve 604 00:29:03,583 --> 00:29:06,440 that had the Kanji writing on it, it was like, 605 00:29:06,440 --> 00:29:09,000 okay, this is Japanese, now all we have to do 606 00:29:09,000 --> 00:29:10,350 is prove that it's Musashi. 607 00:29:12,900 --> 00:29:16,363 - [Narrator] To do that, they need to find the ship's bow. 608 00:29:17,820 --> 00:29:20,000 - [Man] There's the bollards, two bollards. 609 00:29:21,180 --> 00:29:22,480 So we're not too far away. 610 00:29:23,383 --> 00:29:25,730 It'll be above the degaussing cable. 611 00:29:28,963 --> 00:29:30,463 Something's there. 612 00:29:32,183 --> 00:29:33,100 It's there. 613 00:29:35,280 --> 00:29:37,710 - [Narrator] The gold paint is gone, 614 00:29:37,710 --> 00:29:41,460 but the outline of the imperial Japanese flower emblem 615 00:29:41,460 --> 00:29:42,743 is still there. 616 00:29:44,030 --> 00:29:47,840 - As soon as we found the chrysanthemum on the bow, 617 00:29:47,840 --> 00:29:49,443 we knew what we were looking at. 618 00:29:49,443 --> 00:29:53,040 - That's, that's proof positive. 619 00:29:53,040 --> 00:29:56,210 - It wasn't the kind of jumping up and shouting for joy 620 00:29:56,210 --> 00:29:58,530 that I've experienced in the past, 621 00:29:58,530 --> 00:30:01,920 it was a sort of a quiet relief. 622 00:30:01,920 --> 00:30:03,070 We had finally done it. 623 00:30:04,610 --> 00:30:07,970 - [Narrator] At long last, Musashi is found, 624 00:30:07,970 --> 00:30:10,930 but a new, and still more intriguing mystery 625 00:30:10,930 --> 00:30:12,403 is about to emerge. 626 00:30:14,027 --> 00:30:16,440 (soft music) 627 00:30:16,440 --> 00:30:19,630 Over the next week, the search team explores the wreck 628 00:30:19,630 --> 00:30:20,883 of the super battleship. 629 00:30:22,274 --> 00:30:23,874 - There's some shells on the top 630 00:30:25,812 --> 00:30:26,800 - [Rob] I think there's another one 631 00:30:26,800 --> 00:30:30,920 of the mounts for a light, or a-- 632 00:30:30,920 --> 00:30:33,480 - [Narrator] 70 years after she disappeared, 633 00:30:33,480 --> 00:30:36,050 they're compiling the first detailed picture 634 00:30:36,050 --> 00:30:38,463 of a lost technological marvel. 635 00:30:39,890 --> 00:30:41,740 - Because there are no drawings for this ship 636 00:30:41,740 --> 00:30:43,430 and there's only a handful of photographs, 637 00:30:43,430 --> 00:30:45,790 so we're the first people really 638 00:30:45,790 --> 00:30:47,573 to document what she looks like. 639 00:30:48,940 --> 00:30:52,007 - [Narrator] They also find signs of those who sailed her, 640 00:30:52,940 --> 00:30:55,223 a shoe, a helmet, 641 00:30:56,410 --> 00:30:59,175 and something unexpected on a warship. 642 00:30:59,175 --> 00:31:00,280 - [David] That's film. 643 00:31:00,280 --> 00:31:01,330 - [Woman] No, that's film. 644 00:31:01,330 --> 00:31:03,530 - [David] That is a film strip. 645 00:31:03,530 --> 00:31:05,760 It's not just a metal ship, these are crew 646 00:31:05,760 --> 00:31:06,840 that served in it, 647 00:31:06,840 --> 00:31:09,210 and some obviously died on the site as well, 648 00:31:09,210 --> 00:31:11,480 so it's important to document that. 649 00:31:15,250 --> 00:31:17,210 (soft dramatic music) 650 00:31:17,210 --> 00:31:19,240 - [Narrator] Musashi lies a good distance 651 00:31:19,240 --> 00:31:21,180 from the sinking position reported 652 00:31:21,180 --> 00:31:22,553 by the destroyer Kiyoshimo. 653 00:31:24,270 --> 00:31:26,510 (flash bulb pops) 654 00:31:26,510 --> 00:31:29,743 But that's not the only reason she was so hard to find. 655 00:31:31,220 --> 00:31:34,160 - The Musashi is literally on the side of a volcano. 656 00:31:34,160 --> 00:31:36,000 And if you've hiked up a volcano before, 657 00:31:36,000 --> 00:31:38,480 you'd know there's great big huge rocks and outcroppings 658 00:31:38,480 --> 00:31:42,443 and boulders, and so it's hidden inside the geology. 659 00:31:44,420 --> 00:31:47,090 - [Narrator] The difficulty in finding the wreck 660 00:31:47,090 --> 00:31:49,903 is also explained by her shocking condition. 661 00:31:52,560 --> 00:31:54,708 - Just the complete and utter destruction 662 00:31:54,708 --> 00:31:59,020 of the ship itself, the stern and the bow sections 663 00:31:59,020 --> 00:32:02,053 are really the only whole parts of the hull that remain. 664 00:32:02,900 --> 00:32:06,670 The bridge is somewhat intact from what we can see, 665 00:32:06,670 --> 00:32:08,840 but the rest, you know, the center section of the ship 666 00:32:08,840 --> 00:32:10,733 was just completely destroyed. 667 00:32:12,590 --> 00:32:15,430 - So, essentially, it's broken it's back 668 00:32:15,430 --> 00:32:17,730 in at least two different locations. 669 00:32:17,730 --> 00:32:21,480 And for a ship that withstood so many attacks 670 00:32:21,480 --> 00:32:26,000 from torpedoes and bombs and essentially sank intact, 671 00:32:26,000 --> 00:32:27,493 that's more than I expected. 672 00:32:28,680 --> 00:32:30,230 - [Narrator] What then could have caused 673 00:32:30,230 --> 00:32:32,159 such widespread destruction? 674 00:32:32,159 --> 00:32:33,510 (graphics whirring) 675 00:32:33,510 --> 00:32:36,313 It's a question which, so far, has no answer. 676 00:32:37,788 --> 00:32:39,083 (dramatic music) 677 00:32:39,083 --> 00:32:40,140 (guns bang) 678 00:32:40,140 --> 00:32:42,940 One of the last pieces to be discovered 679 00:32:42,940 --> 00:32:45,453 is Musashi's most potent weapon. 680 00:32:46,395 --> 00:32:48,900 (guns banging) 681 00:32:48,900 --> 00:32:52,290 - Which is, obviously, what caught everybody's imagination, 682 00:32:52,290 --> 00:32:55,110 these special 18-inch guns. 683 00:32:55,110 --> 00:32:57,400 These guns are held into the body of the ship, 684 00:32:57,400 --> 00:32:59,420 into the barbettes by gravity alone. 685 00:32:59,420 --> 00:33:03,330 So when the ship capsizes, they're incredibly heavy objects 686 00:33:03,330 --> 00:33:05,430 that just fall out under their own weight. 687 00:33:06,590 --> 00:33:09,253 We found one of these guns after a week of searching. 688 00:33:10,590 --> 00:33:13,010 - [Narrator] By now, the expedition has assembled 689 00:33:13,010 --> 00:33:15,223 an extensive record of Musashi, 690 00:33:16,260 --> 00:33:19,093 over 100 hours of video footage alone. 691 00:33:21,480 --> 00:33:24,210 - We want to make sure that we have fully documented 692 00:33:24,210 --> 00:33:25,910 the condition and the state of the wreck 693 00:33:25,910 --> 00:33:28,210 so we can share that with everybody and, you know, 694 00:33:28,210 --> 00:33:30,380 what we've done here and the data that we've gathered. 695 00:33:30,380 --> 00:33:32,542 We'll provide the clues that people can use 696 00:33:32,542 --> 00:33:35,230 to recreate or have an understanding 697 00:33:35,230 --> 00:33:37,308 of what actually happened. 698 00:33:37,308 --> 00:33:39,820 (light music) 699 00:33:39,820 --> 00:33:42,810 - [Narrator] The search team has opened a door. 700 00:33:42,810 --> 00:33:47,383 Now, others must step in to unravel Musashi's final hours. 701 00:33:49,430 --> 00:33:53,750 In March 2016, a group of Japanese experts assembles 702 00:33:53,750 --> 00:33:56,073 in Tokyo to take up the challenge. 703 00:33:58,270 --> 00:34:01,040 (soft dramatic music) 704 00:34:01,040 --> 00:34:05,110 To help them, the Japanese broadcaster, NHK, 705 00:34:05,110 --> 00:34:07,173 has created a valuable tool. 706 00:34:08,160 --> 00:34:11,630 Like pieces of a gigantic puzzle, it's taken the hours 707 00:34:11,630 --> 00:34:14,573 of digital images gathered by the search expedition, 708 00:34:15,740 --> 00:34:18,293 painstakingly piecing them back together, 709 00:34:19,660 --> 00:34:22,673 and creating a unique 3D model of the wreck. 710 00:34:25,635 --> 00:34:28,635 (graphics whirring) 711 00:34:42,300 --> 00:34:46,470 Only now is Musashi's enormous size apparent. 712 00:34:46,470 --> 00:34:50,610 At 263 meters, some 900 feet, 713 00:34:50,610 --> 00:34:53,193 she's longer than three jumbo jets. 714 00:34:55,165 --> 00:34:59,415 (men speaking in foreign language) 715 00:35:01,180 --> 00:35:04,250 To begin with, these experts want to find out 716 00:35:04,250 --> 00:35:07,340 why a ship so many believed unsinkable 717 00:35:07,340 --> 00:35:10,039 should fail it's first serious test. 718 00:35:10,039 --> 00:35:11,992 (Masami speaks in foreign language) 719 00:35:11,992 --> 00:35:14,230 (man speaks in foreign language) 720 00:35:14,230 --> 00:35:17,370 - [Interpreter] What is that thing that looks like a hole? 721 00:35:17,370 --> 00:35:20,070 - [Narrator] Masami Tezuka has been studying the Musashi 722 00:35:20,070 --> 00:35:21,333 for 30 years. 723 00:35:22,920 --> 00:35:24,963 He believes he's identified one clue, 724 00:35:26,030 --> 00:35:29,480 a damaged section protruding from the port bow, 725 00:35:29,480 --> 00:35:32,934 most likely caused by a torpedo strike. 726 00:35:32,934 --> 00:35:36,530 (Masami speaks in foreign language) 727 00:35:36,530 --> 00:35:38,370 - [Interpreter] Musashi would lose speed as a result, 728 00:35:38,370 --> 00:35:40,840 making it difficult to steer her. 729 00:35:40,840 --> 00:35:42,220 From an attackers point of view, 730 00:35:42,220 --> 00:35:44,390 a battleship that's dragging swuld have been easier to hit 731 00:35:44,390 --> 00:35:45,813 with bombs or torpedoes. 732 00:35:47,980 --> 00:35:49,650 - [Narrator] The last photo of Musashi 733 00:35:49,650 --> 00:35:53,270 shows her down at the bow, leading to the belief 734 00:35:53,270 --> 00:35:55,763 that flooding here caused her to sink. 735 00:35:57,511 --> 00:35:59,790 But a new scientific investigation 736 00:36:00,660 --> 00:36:04,513 at the University of Kobe tells a different story. 737 00:36:06,100 --> 00:36:09,570 Professor Hirotada Hashimoto, a specialist 738 00:36:09,570 --> 00:36:12,563 in naval architecture, conducted the analysis. 739 00:36:13,650 --> 00:36:16,750 When he simulates flooding inside the bow, 740 00:36:16,750 --> 00:36:18,570 the ship does pitch forward. 741 00:36:20,030 --> 00:36:22,770 But results show, water-tight compartments 742 00:36:22,770 --> 00:36:25,873 in the rest of the ship would not have been affected. 743 00:36:26,901 --> 00:36:29,610 (Hirotada speaks in foreign language) 744 00:36:29,610 --> 00:36:31,010 - [Interpreter] Even if the bow, 745 00:36:31,010 --> 00:36:33,740 including the part protected by armored plating, 746 00:36:33,740 --> 00:36:35,750 is completely filled with water, 747 00:36:35,750 --> 00:36:38,740 the ship will still be left with enough buoyancy. 748 00:36:38,740 --> 00:36:41,670 So this flooding alone definitely could not have caused 749 00:36:41,670 --> 00:36:43,873 the ship to sink or capsize. 750 00:36:45,560 --> 00:36:48,650 - [Narrator] To find answers to why Musashi sank, 751 00:36:48,650 --> 00:36:51,681 these experts will have to look elsewhere, 752 00:36:51,681 --> 00:36:55,833 starting in the place where Musashi was constructed. 753 00:36:57,443 --> 00:36:59,940 (soft music) 754 00:36:59,940 --> 00:37:03,050 At the Mitsubishi shipyard in Nagasaki, 755 00:37:03,050 --> 00:37:05,833 the Japanese team makes an important discovery. 756 00:37:07,350 --> 00:37:11,613 A file marked Musashi is uncovered in the company archives. 757 00:37:13,750 --> 00:37:16,200 It contains more than 200 pages 758 00:37:16,200 --> 00:37:19,123 of never-before released original blueprints. 759 00:37:24,400 --> 00:37:26,940 - [Narrator] By comparing images of the scattered pieces 760 00:37:26,940 --> 00:37:29,440 of the wreck with the blueprint, 761 00:37:29,440 --> 00:37:31,663 the team is able to identify them. 762 00:37:32,526 --> 00:37:36,110 (men speaking in foreign language) 763 00:37:36,110 --> 00:37:41,110 A pump, a boiler, all parts protected 764 00:37:41,290 --> 00:37:42,940 by the heavy steel armor 765 00:37:42,940 --> 00:37:45,433 intended to make Musashi unsinkable. 766 00:37:46,660 --> 00:37:47,493 (Akio speaks in foreign language) 767 00:37:47,493 --> 00:37:49,240 - [Interpreter] So the biggest question is 768 00:37:49,240 --> 00:37:50,833 where did the armor go? 769 00:37:52,160 --> 00:37:54,230 - [Narrator] In the high-resolution sonar image 770 00:37:54,230 --> 00:37:58,810 of the debris field, one structure attracts their attention. 771 00:37:58,810 --> 00:38:01,580 Examining video footage from the area, 772 00:38:01,580 --> 00:38:05,040 they discover a 90-foot piece of steel. 773 00:38:05,040 --> 00:38:07,757 It looks like part of the missing armor. 774 00:38:07,757 --> 00:38:09,440 (graphics whirring) 775 00:38:09,440 --> 00:38:11,880 When they match it up to the 3D model, 776 00:38:11,880 --> 00:38:15,013 they find it comes from the hull on the port side. 777 00:38:16,460 --> 00:38:18,093 But how did it come loose? 778 00:38:20,103 --> 00:38:22,190 - Musashi's armor belt was so thick, 779 00:38:22,190 --> 00:38:24,890 that everyone felt very confident onboard the ship, 780 00:38:24,890 --> 00:38:26,520 that they could stand up to the punishment 781 00:38:26,520 --> 00:38:28,440 of any weapon that could be thrown at it. 782 00:38:28,440 --> 00:38:31,983 But, whereas ships making use of a thinner plate 783 00:38:31,983 --> 00:38:35,450 that could be welded, Musashi's armor could not be welded. 784 00:38:35,450 --> 00:38:36,570 It was simply too thick. 785 00:38:36,570 --> 00:38:38,270 And so they turned back their the 19th century 786 00:38:38,270 --> 00:38:41,023 and simply hot riveted the plates together. 787 00:38:42,580 --> 00:38:44,070 - [Narrator] A company that took part 788 00:38:44,070 --> 00:38:46,620 in riveting the armor for Musashi 789 00:38:46,620 --> 00:38:48,633 is still operating in Osaka. 790 00:38:49,540 --> 00:38:53,373 Two workers recreate the technique used at the time 791 00:38:53,373 --> 00:38:56,723 to join these two pieces of armored plate. 792 00:38:56,723 --> 00:38:58,148 (dramatic music) 793 00:38:58,148 --> 00:39:00,981 (machine banging) 794 00:39:01,910 --> 00:39:04,963 A special hammer drives the rivet into place. 795 00:39:07,470 --> 00:39:09,970 (soft music) 796 00:39:10,900 --> 00:39:13,050 - Japanese sailors assigned to Musashi 797 00:39:13,050 --> 00:39:15,410 had great confidence in the ship. 798 00:39:15,410 --> 00:39:17,730 They thought it was unsinkable, and that's because, 799 00:39:17,730 --> 00:39:20,200 above deck, they saw nothing but guns and firepower. 800 00:39:20,200 --> 00:39:21,670 But then below deck, they were aware 801 00:39:21,670 --> 00:39:23,830 that the ship had the thickest armor 802 00:39:23,830 --> 00:39:25,230 of any warship in the world. 803 00:39:26,420 --> 00:39:28,750 - [Narrator] But the Japanese investigation team 804 00:39:28,750 --> 00:39:31,113 doesn't share the sailors' confidence. 805 00:39:32,130 --> 00:39:34,263 (Hayao speaks in foreign language) 806 00:39:34,263 --> 00:39:36,100 - [Interpreter] I think rivets were the problem. 807 00:39:36,100 --> 00:39:38,050 No matter how thick the armor plates were, 808 00:39:38,050 --> 00:39:40,350 they wouldn't last once the rivets came loose. 809 00:39:41,439 --> 00:39:43,040 - [Narrator] Musashi's armor was attached 810 00:39:43,040 --> 00:39:47,133 at a slanting angle to deflect incoming shells. 811 00:39:48,023 --> 00:39:49,450 (man speaks in foreign language) 812 00:39:49,450 --> 00:39:51,850 - [Interpreter] She was built to withstand artillery duels 813 00:39:51,850 --> 00:39:54,030 against other battleships. 814 00:39:54,030 --> 00:39:57,740 But, instead, she was hit by torpedoes and aerial bombs, 815 00:39:57,740 --> 00:40:00,530 which weren't weapons she expected to face 816 00:40:00,530 --> 00:40:01,884 when she was designed. 817 00:40:01,884 --> 00:40:04,467 (guns popping) 818 00:40:05,580 --> 00:40:08,480 - [Narrator] If a torpedo from an attacking aircraft 819 00:40:08,480 --> 00:40:10,960 struck a a joint in the armor plate, 820 00:40:10,960 --> 00:40:13,922 it could cause rivets to fail and seawater 821 00:40:13,922 --> 00:40:16,254 to begin to seep in. 822 00:40:16,254 --> 00:40:19,960 (plane engine roaring) 823 00:40:19,960 --> 00:40:22,360 So how did this apparent vulnerability 824 00:40:22,360 --> 00:40:25,270 to torpedo strikes go unnoticed? 825 00:40:25,270 --> 00:40:26,647 (guns banging) 826 00:40:26,647 --> 00:40:27,745 (light music) 827 00:40:27,745 --> 00:40:31,995 (men speaking in foreign language) 828 00:40:33,150 --> 00:40:35,430 The team discovers early concerns 829 00:40:35,430 --> 00:40:37,553 about this possible design flaw. 830 00:40:39,860 --> 00:40:42,310 A former officer on Musashi, 831 00:40:42,310 --> 00:40:45,480 who earlier served on her sister ship, Yamato, 832 00:40:45,480 --> 00:40:47,923 made this recording before he died. 833 00:40:49,182 --> 00:40:51,890 (Haruo speaks in foreign language) 834 00:40:51,890 --> 00:40:53,478 - [Interpreter] I heard from Yamato's crew 835 00:40:53,478 --> 00:40:56,150 that during a torpedo attack, 836 00:40:56,150 --> 00:40:58,520 although the armor remained intact, 837 00:40:58,520 --> 00:41:00,410 the rivets were blown off, 838 00:41:00,410 --> 00:41:04,670 and, gradually, water started to leak in around the joints. 839 00:41:04,670 --> 00:41:08,700 It made me realize, if we were hit by a lot of torpedoes, 840 00:41:08,700 --> 00:41:10,062 there would be more flooding, 841 00:41:10,062 --> 00:41:11,973 and that could be her weakest point. 842 00:41:13,050 --> 00:41:15,680 - [Narrator] Shigeru Makino, a naval designer 843 00:41:15,680 --> 00:41:18,290 who oversaw the construction of Musashi, 844 00:41:18,290 --> 00:41:23,137 reported similar misgivings, but later wrote, 845 00:41:23,137 --> 00:41:24,857 "The naval authorities decided 846 00:41:24,857 --> 00:41:27,377 "to simply patch the armor joint 847 00:41:27,377 --> 00:41:30,427 "rather than find a permanent solution to the problem." 848 00:41:32,360 --> 00:41:35,610 In the minds of Musashi's 2,400 crewmen, 849 00:41:35,610 --> 00:41:38,490 many still in their teens or early 20s, 850 00:41:38,490 --> 00:41:43,260 the Imperial Japanese Navy instilled a beguiling illusion, 851 00:41:43,260 --> 00:41:48,140 their super battleship was quite simply unsinkable. 852 00:41:49,172 --> 00:41:50,880 (soft music) 853 00:41:50,880 --> 00:41:55,880 One of them, Masahiro Ohishi, believed it to the very end. 854 00:41:55,987 --> 00:41:57,740 (Masahiro speaks in foreign language) 855 00:41:57,740 --> 00:41:59,770 - [Interpreter] Right up till the moment it sank, 856 00:41:59,770 --> 00:42:01,780 I didn't think it could happen. 857 00:42:01,780 --> 00:42:04,190 The Musashi wouldn't even budge an inch 858 00:42:04,190 --> 00:42:06,650 with a torpedo or two striking her. 859 00:42:06,650 --> 00:42:09,713 There would be no flooding, so we were told. 860 00:42:11,610 --> 00:42:13,830 - [Narrator] Musashi also proved vulnerable 861 00:42:13,830 --> 00:42:15,993 to another unanticipated weapon, 862 00:42:17,180 --> 00:42:19,483 armor-piercing bombs from the air, 863 00:42:20,700 --> 00:42:23,145 as the search team discovered. 864 00:42:23,145 --> 00:42:25,130 - [Man] See that's an issue. 865 00:42:25,130 --> 00:42:27,397 - [Rob] Yeah, once you get in there a little tighter-- 866 00:42:28,290 --> 00:42:29,777 - [Narrator] Underwater footage revealed 867 00:42:29,777 --> 00:42:33,383 one of several 3-foot holes rupturing the ships deck. 868 00:42:34,810 --> 00:42:36,380 - In a short section of the bow, 869 00:42:36,380 --> 00:42:38,370 we saw the damage from the bombs. 870 00:42:38,370 --> 00:42:41,780 So that's corroborating what the US pilots were telling us 871 00:42:41,780 --> 00:42:44,690 about the hits they were getting on Musashi. 872 00:42:44,690 --> 00:42:47,420 - These weapons, although they are as crude and as simple 873 00:42:47,420 --> 00:42:50,880 as they can be, sent through the air column, 874 00:42:50,880 --> 00:42:54,400 penetrate decks and can explode below deck. 875 00:42:54,400 --> 00:42:57,763 This, in the end, causes great destruction on Musashi. 876 00:42:58,854 --> 00:43:00,780 (soft dramatic music) 877 00:43:00,780 --> 00:43:03,970 - [Narrator] Now, thanks to the 3D model of the wreck, 878 00:43:03,970 --> 00:43:06,723 the full extent of that destruction can be seen, 879 00:43:07,610 --> 00:43:09,934 especially up on the bridge, where the captain 880 00:43:09,934 --> 00:43:12,203 and many of officers were stationed. 881 00:43:14,700 --> 00:43:18,680 A gaping 20-foot hole gouged into the starboard side 882 00:43:18,680 --> 00:43:20,563 marks where a bomb struck. 883 00:43:24,860 --> 00:43:28,493 One crew member up here miraculously survived. 884 00:43:29,910 --> 00:43:32,633 Kenji Otsuka remembers what happened. 885 00:43:33,928 --> 00:43:37,940 (Kenji speaks in foreign language) 886 00:43:37,940 --> 00:43:40,390 - [Interpreter] All the desks, chairs, everything, 887 00:43:40,390 --> 00:43:42,550 flew to the port side. 888 00:43:42,550 --> 00:43:46,110 Bodies of those who were killed were piled up there, too. 889 00:43:46,110 --> 00:43:49,440 The blast wave knocked us over, killing some. 890 00:43:49,440 --> 00:43:52,020 One man lost everything from his neck up, 891 00:43:52,020 --> 00:43:54,070 sitting in a chair about 10-feet 892 00:43:54,070 --> 00:43:57,093 from where I was, just dead. 893 00:44:00,730 --> 00:44:03,450 - [Narrator] Standing on an open observation deck, 894 00:44:03,450 --> 00:44:07,570 Captain Inoguchi suffered a shrapnel wound in the shoulder. 895 00:44:07,570 --> 00:44:09,543 Protected from the fire himself, 896 00:44:10,400 --> 00:44:12,833 crewman Kotaki observed what happened. 897 00:44:13,797 --> 00:44:15,790 (Tatsuo speaks in foreign language) 898 00:44:15,790 --> 00:44:17,220 - [Interpreter] I saw him from behind. 899 00:44:17,220 --> 00:44:20,250 He was covering his shoulder with his hand like this, 900 00:44:20,250 --> 00:44:24,130 holding binoculars like this, and giving commands. 901 00:44:24,130 --> 00:44:27,810 Any ordinary person would have collapsed from such injuries. 902 00:44:27,810 --> 00:44:30,337 I thought, "That's a true commander." 903 00:44:31,450 --> 00:44:33,040 - [Narrator] Like her brave captain, 904 00:44:33,040 --> 00:44:35,160 Musashi sustained multiple hits 905 00:44:35,160 --> 00:44:37,823 from weapons she was never designed to face. 906 00:44:39,270 --> 00:44:42,520 Incredibly, her unusual strength allowed her 907 00:44:42,520 --> 00:44:46,263 to go down in one piece, leaving one final question, 908 00:44:47,250 --> 00:44:49,907 what tore her to pieces as she sank? 909 00:44:49,907 --> 00:44:52,651 (water splashing) 910 00:44:52,651 --> 00:44:54,333 (dramatic music) 911 00:44:54,333 --> 00:44:55,672 - [David] That's a 46-centimeter shell 912 00:44:55,672 --> 00:44:56,883 underneath there, right? 913 00:44:57,750 --> 00:44:58,960 - [Narrator] When the search team 914 00:44:58,960 --> 00:45:01,220 originally discovered Musashi-- 915 00:45:01,220 --> 00:45:03,020 - The turret housing was blown away. 916 00:45:04,340 --> 00:45:05,800 - [Narrator] They couldn't believe the wreckage 917 00:45:05,800 --> 00:45:08,193 was spread over such a wide area, 918 00:45:09,750 --> 00:45:14,120 a square kilometer, more than half a square mile. 919 00:45:14,120 --> 00:45:16,020 - Most of the shipwrecks that I've done 920 00:45:16,020 --> 00:45:17,830 are in deeper water than this, 921 00:45:17,830 --> 00:45:21,160 and we're seeing debris fields of 300 meters, 400 meters. 922 00:45:21,160 --> 00:45:23,690 So to see one twice or three times that size 923 00:45:23,690 --> 00:45:25,720 is really telling me that not only 924 00:45:25,720 --> 00:45:27,070 are we dealing with a large ship, 925 00:45:27,070 --> 00:45:29,164 but a large ship that has been blown apart. 926 00:45:29,164 --> 00:45:30,470 (man speaks in foreign language) 927 00:45:30,470 --> 00:45:33,920 - [Narrator] How does a ship that left the surface intact 928 00:45:33,920 --> 00:45:37,840 now lie shattered over the ocean floor? 929 00:45:37,840 --> 00:45:40,930 The Japanese team is determined to find an answer 930 00:45:40,930 --> 00:45:43,633 to this final mystery of Musashi. 931 00:45:43,633 --> 00:45:46,230 (man speaks in foreign language) 932 00:45:46,230 --> 00:45:47,930 - [Interpreter] I'm not sure if it came from a boiler 933 00:45:47,930 --> 00:45:50,530 or something else, but is it possible 934 00:45:50,530 --> 00:45:52,793 this damage was caused by steam exploding? 935 00:45:53,810 --> 00:45:55,860 - [Narrator] One member doesn't think so. 936 00:45:57,348 --> 00:45:59,140 Masatake Yoshida has been studying explosives 937 00:45:59,140 --> 00:46:01,150 for over 30 years. 938 00:46:01,150 --> 00:46:04,788 He believes something else tore Musashi apart. 939 00:46:04,788 --> 00:46:07,820 (Masatake speak in foreign language) 940 00:46:07,820 --> 00:46:09,480 - [Interpreter] I can't think of any explanation 941 00:46:09,480 --> 00:46:11,830 besides a gunpowder explosion. 942 00:46:11,830 --> 00:46:13,920 If an explosion like that occurred, 943 00:46:13,920 --> 00:46:16,677 her internal parts would have shattered into many pieces. 944 00:46:16,677 --> 00:46:18,950 (soft music) 945 00:46:18,950 --> 00:46:19,783 - [Narrator] But where did 946 00:46:19,783 --> 00:46:21,943 this massive explosion take place? 947 00:46:22,780 --> 00:46:25,120 One piece of debris in particular 948 00:46:25,120 --> 00:46:26,933 has caught Yoshida's attention. 949 00:46:28,510 --> 00:46:31,283 Although mangled almost beyond recognition, 950 00:46:32,120 --> 00:46:35,020 it's part of the magazine, holding the shells 951 00:46:35,020 --> 00:46:37,193 for one of Musashi's main guns. 952 00:46:38,128 --> 00:46:42,950 (Masatake speaks in foreign language) 953 00:46:42,950 --> 00:46:44,110 - [Interpreter] Thick steel like this 954 00:46:44,110 --> 00:46:46,800 wouldn't have ended up being so badly twisted 955 00:46:46,800 --> 00:46:48,290 if the ship had just sunk. 956 00:46:49,740 --> 00:46:51,850 - [Narrator] Since Musashi fired her main guns 957 00:46:51,850 --> 00:46:55,360 only a handful of times during her final battle, 958 00:46:55,360 --> 00:46:59,560 an estimated 160 shells and 100 tons of gunpowder 959 00:46:59,560 --> 00:47:01,263 were still stored inside her. 960 00:47:03,149 --> 00:47:05,420 (soft dramatic music) 961 00:47:05,420 --> 00:47:08,310 Suspicion as to where the explosion occurred 962 00:47:08,310 --> 00:47:10,806 falls on the second main gun. 963 00:47:10,806 --> 00:47:12,050 - [David] So that was literally-- 964 00:47:12,050 --> 00:47:13,400 - [Narrator] And firsthand reports 965 00:47:13,400 --> 00:47:16,790 David Mearns uncovered seem to support it. 966 00:47:16,790 --> 00:47:18,990 - To see that level of damage on the seafloor 967 00:47:18,990 --> 00:47:22,800 tells me only one thing, that the Japanese survivors 968 00:47:22,800 --> 00:47:25,970 who heard explosions as it was capsizing, 969 00:47:25,970 --> 00:47:28,593 those explosions were actually magazine explosions. 970 00:47:30,670 --> 00:47:31,920 - [Narrator] In the final moments, 971 00:47:31,920 --> 00:47:35,090 as Musashi heeled over and sank, 972 00:47:35,090 --> 00:47:37,960 a few eyewitnesses aboard a nearby destroyer 973 00:47:37,960 --> 00:47:41,013 reported seeing the flash from a small explosion. 974 00:47:41,913 --> 00:47:44,090 (Masatake speaks in foreign language) 975 00:47:44,090 --> 00:47:45,360 - [Interpreter] Which means that some fires 976 00:47:45,360 --> 00:47:47,730 were already burning inside her. 977 00:47:47,730 --> 00:47:49,760 That makes me think that initial combustion 978 00:47:49,760 --> 00:47:52,673 rapidly spread into an explosion. 979 00:47:52,673 --> 00:47:56,600 Gunpowder contains some oxygen, so even underwater 980 00:47:56,600 --> 00:47:59,670 where there's none, under the right conditions, 981 00:47:59,670 --> 00:48:02,470 a combustive explosion can occur. 982 00:48:02,470 --> 00:48:04,360 - [Narrator] To test his hypothesis, 983 00:48:04,360 --> 00:48:07,453 Dr. Yoshida ran a computer simulation. 984 00:48:09,101 --> 00:48:13,050 It clearly shows a ship made of heavy steel 985 00:48:13,050 --> 00:48:15,266 would have suffered catastrophic damage 986 00:48:15,266 --> 00:48:18,657 from an explosion below her second main gun. 987 00:48:18,657 --> 00:48:21,460 (dramatic music) 988 00:48:21,460 --> 00:48:23,440 The ships core would have splintered 989 00:48:23,440 --> 00:48:25,250 into hundreds of small pieces 990 00:48:26,230 --> 00:48:30,023 with only the bow and stern remaining relatively intact. 991 00:48:33,100 --> 00:48:36,440 The high-resolution sonar map confirms, 992 00:48:36,440 --> 00:48:39,043 this is how the wreck rests on the seafloor. 993 00:48:44,370 --> 00:48:47,500 David Mearns believes other factors also contributed 994 00:48:47,500 --> 00:48:50,970 to the massive damage sustained by Musashi. 995 00:48:50,970 --> 00:48:53,781 (soft dramatic music) 996 00:48:53,781 --> 00:48:57,310 - We see that a large section of the bow was imploded 997 00:48:57,310 --> 00:48:58,900 and we can look at the drawings and know 998 00:48:58,900 --> 00:49:00,750 that there's water-tight compartments in there, 999 00:49:00,750 --> 00:49:03,733 and they've squeezed as the ship sank very quickly. 1000 00:49:05,450 --> 00:49:08,110 - [Narrator] As Musashi plummets to the bottom, 1001 00:49:08,110 --> 00:49:11,210 a crushing pressure, equivalent to the weight of a car, 1002 00:49:11,210 --> 00:49:13,463 bears down on every square inch. 1003 00:49:14,905 --> 00:49:17,210 - When it hits the sea bed, it's hitting the seabed, 1004 00:49:17,210 --> 00:49:19,760 actually, at very high speed, probably a minimum 1005 00:49:19,760 --> 00:49:22,670 of 15 knots, maybe as much as 25 knots. 1006 00:49:22,670 --> 00:49:24,083 And there's impact damage. 1007 00:49:24,960 --> 00:49:27,763 And all of this was evident in one section of the bow. 1008 00:49:30,770 --> 00:49:33,670 - [Narrator] Somewhere in Musashi's twisted remains 1009 00:49:33,670 --> 00:49:36,973 lies her captain, Toshihira Inoguchi. 1010 00:49:37,924 --> 00:49:39,640 He went down with his ship 1011 00:49:39,640 --> 00:49:41,883 after handing over his final report. 1012 00:49:44,242 --> 00:49:47,947 In it, he wrote, "I am truly glad 1013 00:49:47,947 --> 00:49:51,113 "that the other battleship suffered almost no damage, 1014 00:49:52,237 --> 00:49:54,727 "and I feel some consolation in thinking 1015 00:49:54,727 --> 00:49:58,277 "that Musashi was able to assume the role of a victim." 1016 00:50:00,793 --> 00:50:02,617 (dramatic music) 1017 00:50:02,617 --> 00:50:04,264 (plane engines roaring) 1018 00:50:04,264 --> 00:50:05,507 (torpedoes banging) 1019 00:50:05,507 --> 00:50:06,920 - [Narrator] Musashi bore the brunt 1020 00:50:06,920 --> 00:50:10,700 of the American air assault on October 24th, 1944, 1021 00:50:10,700 --> 00:50:13,785 (torpedoes banging) 1022 00:50:13,785 --> 00:50:17,780 leaving most of Japan's Center Force unscathed, 1023 00:50:17,780 --> 00:50:20,093 including the super battleship, Yamato. 1024 00:50:23,570 --> 00:50:25,720 Undetected, Admiral Kurita 1025 00:50:25,720 --> 00:50:28,770 and his 20 remaining ships steamed through the night 1026 00:50:32,330 --> 00:50:34,630 heading for the American landing site at Leyte 1027 00:50:38,000 --> 00:50:41,443 to catch the defending force from 7th fleet by surprise. 1028 00:50:45,430 --> 00:50:49,261 On October 25th, led by the super battleship, Yamato, 1029 00:50:49,261 --> 00:50:50,094 (guns banging) 1030 00:50:50,094 --> 00:50:53,390 the Japanese Navy launched the decisive surface attack 1031 00:50:53,390 --> 00:50:54,423 it had long sought. 1032 00:50:56,970 --> 00:50:59,370 But a bold strike by American destroyers 1033 00:50:59,370 --> 00:51:01,910 and destroyer escorts managed to confuse 1034 00:51:01,910 --> 00:51:03,283 the Japanese commander. 1035 00:51:06,520 --> 00:51:09,650 - And so Admiral Kurita makes the fateful decision 1036 00:51:09,650 --> 00:51:12,560 to reverse course, and in so doing, 1037 00:51:12,560 --> 00:51:15,555 he walks away from what would have been 1038 00:51:15,555 --> 00:51:19,990 the most lopsided victory of the Japanese Imperial Navy 1039 00:51:19,990 --> 00:51:21,190 in the Second World War. 1040 00:51:22,410 --> 00:51:24,100 - [Narrator] Japan's Navy had gambled 1041 00:51:24,100 --> 00:51:26,400 on winning the world's biggest sea battle 1042 00:51:26,400 --> 00:51:28,803 to bring America to the negotiating table. 1043 00:51:30,060 --> 00:51:32,113 But they made a fatal miscalculation. 1044 00:51:33,095 --> 00:51:35,770 Surface ships with big guns 1045 00:51:35,770 --> 00:51:38,393 were no longer the dominant force at sea. 1046 00:51:40,740 --> 00:51:42,210 - The age of the battleships, 1047 00:51:42,210 --> 00:51:45,750 the building and the loss of the Musashi is the endpoint. 1048 00:51:45,750 --> 00:51:48,010 They weren't gonna be defeated by another battleship, 1049 00:51:48,010 --> 00:51:50,850 another great battleship, but by aircraft. 1050 00:51:50,850 --> 00:51:54,777 And that's when the era of aircraft carriers took off. 1051 00:51:59,993 --> 00:52:03,160 (soft dramatic music) 1052 00:52:06,400 --> 00:52:11,400 On October 24th, 2016, at Yasukuni Shrine in Tokyo, 1053 00:52:11,980 --> 00:52:14,410 surviving crew members from Musashi 1054 00:52:14,410 --> 00:52:16,773 gathered to remember their lost comrades. 1055 00:52:18,520 --> 00:52:21,780 The discovery of the wreck and the evidence it reveals 1056 00:52:21,780 --> 00:52:25,113 of Musashi's vulnerability is a cruel reminder, 1057 00:52:26,310 --> 00:52:28,073 this was not the unsinkable battleships 1058 00:52:28,073 --> 00:52:30,063 they were led to believe her to be. 1059 00:52:32,430 --> 00:52:33,913 But for crewman Tsukada, 1060 00:52:34,800 --> 00:52:37,333 the wreck still bears an important message. 1061 00:52:38,927 --> 00:52:41,460 (Yoshiaki speaks in foreign language) 1062 00:52:41,460 --> 00:52:42,726 - [Interpreter] I think the Musashi 1063 00:52:42,726 --> 00:52:44,370 would like the people to know 1064 00:52:44,370 --> 00:52:47,430 how bravely her crew members fought and died. 1065 00:52:47,430 --> 00:52:49,942 What an astonishing battleship she was, 1066 00:52:49,942 --> 00:52:53,200 how she fought and met her tragic end 1067 00:52:53,200 --> 00:52:57,630 in the emptiness of war, I think those are the messages 1068 00:52:57,630 --> 00:53:00,672 that the Musashi wants to send us. 1069 00:53:00,672 --> 00:53:03,720 (soft music) 1070 00:53:03,720 --> 00:53:06,174 - [Narrator] For Bob Freligh, an American pilot who launched 1071 00:53:06,174 --> 00:53:09,326 one of the many torpedoes that sank her, 1072 00:53:09,326 --> 00:53:13,333 Musashi's discovery stirs thoughts of reconciliation. 1073 00:53:14,410 --> 00:53:17,210 - I don't want any Japanese survivor 1074 00:53:17,210 --> 00:53:21,340 to think that I'm trying to laud these medals over them. 1075 00:53:21,340 --> 00:53:24,300 Our opportunity is, we have a common ground. 1076 00:53:24,300 --> 00:53:26,880 They are survivors of the same action 1077 00:53:26,880 --> 00:53:29,030 that I'm a survivor of, 1078 00:53:29,030 --> 00:53:33,753 and I'd just like to say, welcome, brother. 1079 00:53:39,615 --> 00:53:42,198 (bell dinging) 1080 00:53:43,237 --> 00:53:44,910 - "At the going down with the sun, 1081 00:53:44,910 --> 00:53:47,873 and in the morning we will remember them." 1082 00:53:47,873 --> 00:53:50,373 - [All] We will remember them. 1083 00:53:51,470 --> 00:53:52,580 - [Narrator] Above the wreck site 1084 00:53:52,580 --> 00:53:54,250 in the Sibuyan Sea, (somber horn music) 1085 00:53:54,250 --> 00:53:57,523 the crew of the Octopus pay their own final respects. 1086 00:53:58,434 --> 00:54:00,300 - It is a war grave. 1087 00:54:00,300 --> 00:54:02,900 You know, we as sailors and seafarers ourselves, 1088 00:54:02,900 --> 00:54:05,077 we have a lot of respect for what happened here. 1089 00:54:05,077 --> 00:54:07,870 (soft music) 1090 00:54:07,870 --> 00:54:09,545 - [Narrator] Instead of warplanes, 1091 00:54:09,545 --> 00:54:12,083 they launch a flight of paper cranes, 1092 00:54:13,640 --> 00:54:15,550 symbol of the peace that has endured 1093 00:54:15,550 --> 00:54:18,032 for three-quarters of a century 1094 00:54:18,032 --> 00:54:20,913 between once bitter enemies of World War II. 1095 00:54:27,286 --> 00:54:30,619 (soft dramatic music)