1 00:00:07,508 --> 00:00:09,910 (speaking in German) 2 00:00:09,943 --> 00:00:12,913 NARRATOR: Hitler's darkest secrets... 3 00:00:14,815 --> 00:00:17,318 And most terrifying weapons... 4 00:00:20,688 --> 00:00:24,858 Lost below the waves, until now. 5 00:00:28,096 --> 00:00:32,866 Imagine if we could empty the oceans, letting the water drain away 6 00:00:34,135 --> 00:00:37,471 to reveal the secrets of the sea floor. 7 00:00:40,040 --> 00:00:42,643 Now we can. 8 00:00:44,445 --> 00:00:48,249 Using the latest underwater scanning technology... 9 00:00:48,516 --> 00:00:50,451 Piercing the deep oceans... 10 00:00:50,484 --> 00:00:54,088 And turning accurate data into 3D images. 11 00:00:56,124 --> 00:00:57,991 This time... 12 00:00:58,025 --> 00:01:02,196 was Australia's most prized warship destroyed by a Nazi secret weapon? 13 00:01:07,067 --> 00:01:10,904 What made this killer U-boat invisible? 14 00:01:13,441 --> 00:01:18,011 And how close did Hitler come to building an atomic bomb? 15 00:01:23,684 --> 00:01:29,990 (theme music plays) 16 00:01:39,200 --> 00:01:42,303 Hitler's ambition was global. 17 00:01:42,670 --> 00:01:48,041 As the waters of Northern Europe drain away they reveal evidence of the Nazis most 18 00:01:48,075 --> 00:01:50,344 terrifying weapon of all. 19 00:01:52,112 --> 00:01:55,048 Norway, Lake Tinn. 20 00:01:56,784 --> 00:02:01,989 How did a secret operation here destroy a Nazi nuclear dream? 21 00:02:04,124 --> 00:02:07,195 RUNAR: At the bottom, there's this Nazi secret. 22 00:02:07,461 --> 00:02:09,897 No one can be sure about what's down there. 23 00:02:13,867 --> 00:02:19,307 NARRATOR: During World War II, Nazi scientists begin the race to harness atomic power. 24 00:02:21,742 --> 00:02:26,113 -Hitler's dream was to develop this bomb that could really 25 00:02:27,080 --> 00:02:30,251 devastate and destroy London... 26 00:02:34,121 --> 00:02:36,590 turning the war in the blink of a second. 27 00:02:36,624 --> 00:02:38,726 That was his dream. 28 00:02:45,433 --> 00:02:49,303 NARRATOR: But the Nazis need a crucial ingredient to make an atomic bomb. 29 00:02:50,871 --> 00:02:53,274 It's called heavy water. 30 00:02:54,508 --> 00:02:58,346 ERIC: Heavy water was a vital component of the attempt of the Germans to get their 31 00:02:59,713 --> 00:03:02,115 nuclear reactor to work. 32 00:03:02,716 --> 00:03:06,487 It's chemically hydrogen but it's heavier, it's twice the weight. 33 00:03:09,890 --> 00:03:14,528 NARRATOR: The world's largest producer of heavy water is near Lake Tinn in Norway. 34 00:03:19,199 --> 00:03:24,305 Vemork Power Plant, once the world's largest hydro-electric power station. 35 00:03:28,309 --> 00:03:33,414 It is this energy that powers the creation of the precious heavy water. 36 00:03:36,250 --> 00:03:39,353 April the 9th, 1940. 37 00:03:39,687 --> 00:03:42,122 Germany invades Norway. 38 00:03:45,993 --> 00:03:50,798 -The Nazis were eager to get control of the heavy water at the Vemork plant, 39 00:03:51,299 --> 00:03:56,870 due to the reason that they wanted to use it as a cooling aid in their nuclear reactor. 40 00:03:59,640 --> 00:04:05,112 In 1942 at the peak of the production here at Vemork, they produced as much as 41 00:04:05,546 --> 00:04:09,617 1,000 kilos of heavy water. 42 00:04:10,083 --> 00:04:15,022 NARRATOR: Over a ton is a big step towards building Hitler's first nuclear reactor. 43 00:04:18,258 --> 00:04:22,496 -It looked as if Germany might well get a nuclear bomb quickly and the Allies were 44 00:04:22,996 --> 00:04:26,066 obviously very concerned about that. 45 00:04:26,900 --> 00:04:30,438 Churchill wanted the heavy water plant to be destroyed. 46 00:04:32,306 --> 00:04:37,511 NARRATOR: Vemork Power Plant becomes a priority target for Allied air raids and sabotage. 47 00:04:39,713 --> 00:04:44,452 Damage like this eventually forces the Nazis to safeguard their stockpile of the 48 00:04:44,485 --> 00:04:46,820 precious commodity. 49 00:04:49,390 --> 00:04:52,493 February 20th, 1944. 50 00:04:53,727 --> 00:04:58,832 The Nazis plan to move almost a year's output of heavy water by train from Vemork. 51 00:05:00,734 --> 00:05:04,004 The carriages will cross Lake Tinn by ferry. 52 00:05:05,072 --> 00:05:09,610 From here the cargo will travel to Germany, to the site of a nuclear reactor. 53 00:05:14,314 --> 00:05:17,751 Soldiers load around 40 barrels on to railway carriages. 54 00:05:20,921 --> 00:05:24,024 The hydro ferry departs... 55 00:05:24,892 --> 00:05:27,461 But it never reaches its destination. 56 00:05:29,697 --> 00:05:36,036 At 10:45 in the morning it sinks, the cargo tumbles into the water. 57 00:05:37,304 --> 00:05:43,310 27 people are rescued, 26 go down with the ferry, mostly innocent civilians. 58 00:05:48,115 --> 00:05:52,285 For decades the hydro ferry and her secret wartime cargo lie 59 00:05:52,319 --> 00:05:56,023 hidden in the dark waters... 60 00:05:57,190 --> 00:06:00,327 until now. 61 00:06:04,898 --> 00:06:08,335 Fredrik Soreide is a maritime archaeologist. 62 00:06:09,703 --> 00:06:13,273 He has studied this area for over 20 years. 63 00:06:15,208 --> 00:06:18,078 FREDRIK: I'm standing on the shores of Lake Tinn. 64 00:06:18,111 --> 00:06:20,881 It's a very dramatic lake in Norway. 65 00:06:20,914 --> 00:06:27,020 It's got high mountains up to 1,000 meters around it and the lake is very deep so it 66 00:06:27,521 --> 00:06:31,258 actually goes down to 460 meters. 67 00:06:33,293 --> 00:06:39,232 For decades this lake had a big secret and to be able to uncover that secret the whole 68 00:06:40,668 --> 00:06:43,504 lake had to be explored. 69 00:06:45,506 --> 00:06:52,012 NARRATOR: 1500 feet is too deep for divers so Fredrik works with an expert in 70 00:06:52,813 --> 00:06:57,317 remotely operated vehicles, Thor-Olav Sperre. 71 00:06:58,118 --> 00:07:01,221 FREDRIK: So today we have the remotely operated vehicle. 72 00:07:02,089 --> 00:07:07,961 It is used to go down to the shipwreck so that we can film it and also make 73 00:07:07,995 --> 00:07:11,431 a lot of other interesting documentation. 74 00:07:12,666 --> 00:07:16,870 NARRATOR: They're equipping the ROV with the latest multi-beam sonar technology, 75 00:07:17,404 --> 00:07:20,674 allowing them to probe the darkest depths. 76 00:07:21,141 --> 00:07:24,478 THOR-OLAV: Take it up and then we can load a new profile and then start 77 00:07:24,512 --> 00:07:25,779 doing the other tests. 78 00:07:25,813 --> 00:07:27,615 -Yeah. 79 00:07:27,648 --> 00:07:30,317 NARRATOR: Multi-beam sonar fires sound waves to the lake floor. 80 00:07:33,053 --> 00:07:37,057 The return signal displays the shape and depth of the features beneath. 81 00:07:38,458 --> 00:07:41,795 -It becomes then a very detailed image and that's what we're looking at, 82 00:07:42,029 --> 00:07:43,463 that's what we want. 83 00:07:43,497 --> 00:07:45,999 NARRATOR: And Thor-Olav knows where to look. 84 00:07:47,300 --> 00:07:51,471 He's been fascinated by the story of the lost ferry for years and he was 85 00:07:51,505 --> 00:07:54,942 one of the first to find the wreck. 86 00:07:55,709 --> 00:08:00,180 Now, he's back, with powerful new scanning equipment and 87 00:08:00,213 --> 00:08:05,052 cameras that will finally give him the most detailed record of what's down there. 88 00:08:11,291 --> 00:08:15,629 Eventually a ghostly shape looms into view. 89 00:08:26,206 --> 00:08:30,510 The icy depths of the freshwater lake have preserved the decades old secret. 90 00:08:33,714 --> 00:08:36,316 -Ah, there we go, oh there it is. 91 00:08:36,349 --> 00:08:41,054 -I see the frame. -Where are we now? -On the starboard. 92 00:08:43,691 --> 00:08:46,026 -Very nice. 93 00:08:49,096 --> 00:08:53,233 -The super structure is still standing there and we can see a lot of things 94 00:08:54,201 --> 00:08:57,237 on board still. 95 00:08:59,239 --> 00:09:02,743 -Yeah. We're only 3 and a half meters above it. 96 00:09:06,814 --> 00:09:09,717 -Ah look, that's a, is that a railway carriage? 97 00:09:09,750 --> 00:09:12,419 -Yes it is, upside down. -It's upside down. 98 00:09:13,453 --> 00:09:15,656 Oh it's been thrown over. 99 00:09:15,689 --> 00:09:18,659 Yeah, that's the wheels. 100 00:09:19,860 --> 00:09:23,296 NARRATOR: The cargo on these carriages was once destined for Nazi Germany. 101 00:09:25,699 --> 00:09:30,704 Instead it lies deep in the darkness of a Norwegian lake. 102 00:09:31,939 --> 00:09:35,709 But why is the ferry here? 103 00:09:38,912 --> 00:09:44,918 For the very first time the waters of Lake Tinn drain away to reveal the true picture. 104 00:09:47,688 --> 00:09:51,825 Using multi-beam sonar data combined with cutting edge computer graphics, 105 00:09:52,893 --> 00:09:57,464 the lake's astonishing underwater landscape comes clearly into view. 106 00:10:03,904 --> 00:10:07,941 The first clue lies in the shape of the valley itself. 107 00:10:08,642 --> 00:10:13,513 There are steep banks which descend 1500 feet down, to the bottom of the 108 00:10:13,546 --> 00:10:16,316 one of the deepest lakes in Europe. 109 00:10:17,617 --> 00:10:21,521 As the waters of the lake drain fully away... 110 00:10:21,889 --> 00:10:25,659 the drowned ferry is brought back into the light of day for the 111 00:10:25,693 --> 00:10:29,129 first time in over 70 years. 112 00:10:31,999 --> 00:10:36,469 First the stern of the 170-foot-long vessel, tilting downwards. 113 00:10:41,041 --> 00:10:44,311 Then the wreckage of the railway carriages... 114 00:10:46,680 --> 00:10:50,217 and the captain's wheelhouse. 115 00:10:52,720 --> 00:10:57,590 The spread of the wreckage is firm evidence of a catastrophic, sudden sinking. 116 00:11:01,028 --> 00:11:05,899 FREDRIK: Here we can clearly see the wreck and we can see the wheelhouse up here and we 117 00:11:05,933 --> 00:11:10,070 can see there's something behind here. Maybe.... 118 00:11:10,103 --> 00:11:12,672 THOR-OLAV: Ah the bow is probably down in the mud. 119 00:11:13,273 --> 00:11:16,509 NARRATOR: So what wrecked the ferry? 120 00:11:16,543 --> 00:11:22,115 The answer is one of the most daring sabotage operations of World War II. 121 00:11:26,386 --> 00:11:31,224 Norwegian resistance fighters learn about the Nazi heavy water shipment. 122 00:11:31,792 --> 00:11:35,328 They are ordered by London to stop it at all costs. 123 00:11:42,469 --> 00:11:46,073 The night before the ferry departs, under cover of darkness, 124 00:11:47,007 --> 00:11:49,709 the saboteurs board the vessel and place a 125 00:11:49,743 --> 00:11:54,214 time bomb set to detonate at a precise moment, 126 00:11:54,247 --> 00:11:57,684 then leave the ship to its fate. 127 00:11:58,986 --> 00:12:02,122 -The saboteurs knew the stakes couldn't be higher. 128 00:12:03,791 --> 00:12:07,227 They had to stop the transportation to Germany. 129 00:12:07,727 --> 00:12:10,363 (ticking) 130 00:12:10,397 --> 00:12:13,633 (explosion) 131 00:12:20,908 --> 00:12:26,679 NARRATOR: Draining Lake Tinn reveals that the ferry is precisely targeted to sink in 132 00:12:26,713 --> 00:12:29,516 the deepest part of the lake. 133 00:12:30,250 --> 00:12:35,956 No Nazi diver can ever retrieve the barrels of heavy water from these depths but is 134 00:12:35,989 --> 00:12:40,393 the ferry carrying enough heavy water to give Hitler an atomic bomb? 135 00:12:47,868 --> 00:12:52,705 NARRATOR: Draining Lake Tinn in Norway reveals an infamous Nazi nuclear secret 136 00:12:53,473 --> 00:12:56,343 strewn across the lake bed. 137 00:12:57,144 --> 00:13:01,281 Was there enough heavy water on board to make the Nazis nuclear bomb 138 00:13:01,314 --> 00:13:03,716 program go critical? 139 00:13:06,186 --> 00:13:10,790 -After the ferry went down there was a lot of speculation that the heavy water on board 140 00:13:11,124 --> 00:13:16,696 the hydro had been replaced by normal water because it was so lightly guarded. 141 00:13:17,030 --> 00:13:21,801 So we wanted to go down and take up a barrel to prove that this was in fact 142 00:13:21,835 --> 00:13:24,704 the heavy water that was being shipped to Germany. 143 00:13:27,107 --> 00:13:30,911 NARRATOR: The team have already examined three barrels from the depths. 144 00:13:31,144 --> 00:13:34,882 -Aye aye, yes. 145 00:13:36,016 --> 00:13:41,154 NARRATOR: Testing samples taken from inside the barrels proves that they do contain 146 00:13:41,188 --> 00:13:47,127 heavy water but was the ferry's cargo large enough to help Hitler build 147 00:13:48,061 --> 00:13:50,630 an atomic bomb? 148 00:13:52,132 --> 00:13:56,636 The only way to find out is to probe the darkness of Lake Tinn and see how 149 00:13:56,669 --> 00:13:59,907 many barrels are left. 150 00:14:02,876 --> 00:14:07,447 Draining the waters of this Norwegian lake unlocks the answers. 151 00:14:09,749 --> 00:14:13,420 Amazingly, still intact after more than 70 years. 152 00:14:16,256 --> 00:14:20,860 First, one barrel on the deck then 2 more spilled over the side... 153 00:14:24,497 --> 00:14:28,035 then 2 others, 60 feet from the wreck site. 154 00:14:31,471 --> 00:14:34,441 That's 5 barrels visible around the wreck. 155 00:14:37,310 --> 00:14:40,113 FREDRIK: Well you can still see numbers on the barrels, yeah? 156 00:14:42,015 --> 00:14:45,152 We believe that maybe 10 barrels floated because they were not full, 157 00:14:46,886 --> 00:14:49,923 and we have picked up 3 barrels. 158 00:14:50,323 --> 00:14:54,461 NARRATOR: With at least 18 barrels accounted for and using the scan data 159 00:14:54,494 --> 00:14:59,099 as a guide, the survey team can calculate where the others are. 160 00:15:00,600 --> 00:15:04,504 -We believe that most of the other barrels are actually on board the ferry, still, 161 00:15:05,605 --> 00:15:08,541 underneath turned over carriages. 162 00:15:09,342 --> 00:15:14,081 NARRATOR: That's about half a ton of heavy water, enough to be a vital missing 163 00:15:14,114 --> 00:15:16,849 component for the Nazis nuclear reactor. 164 00:15:21,321 --> 00:15:25,192 -After the war those involved in the German nuclear program said 165 00:15:25,225 --> 00:15:27,860 that the loss of the heavy water was absolutely decisive. 166 00:15:27,894 --> 00:15:31,698 It stopped their reactor program in its tracks. 167 00:15:36,469 --> 00:15:40,407 (speaking in German) 168 00:15:40,440 --> 00:15:45,312 NARRATOR: Nazi secret weapons are deployed right across the globe, 169 00:15:46,813 --> 00:15:50,217 including the Indian Ocean. 170 00:15:50,450 --> 00:15:55,122 Draining the waters here, off the coast of Western Australia reveals 171 00:15:55,622 --> 00:15:58,525 two shattered wrecks... 172 00:16:00,627 --> 00:16:05,532 What appears to be a German merchant ship and HMAS Sydney. 173 00:16:09,136 --> 00:16:13,906 This mighty Australian warship disappears in November 1941. 174 00:16:15,942 --> 00:16:20,880 Will draining HMAS Sydney uncover the mystery of what happened in 175 00:16:20,913 --> 00:16:23,483 the national disaster? 176 00:16:24,051 --> 00:16:28,621 JANN: For the Australians, the loss of the Sydney almost became something 177 00:16:28,921 --> 00:16:30,957 like a national trauma. 178 00:16:30,990 --> 00:16:34,894 It was the pride of the Australian Navy. 179 00:16:35,695 --> 00:16:41,434 Not knowing about her final resting place and the fate of her crew puzzled 180 00:16:42,302 --> 00:16:45,672 the Australians for decades. 181 00:16:46,906 --> 00:16:50,377 NARRATOR: After the war, a German captain, Theodore Detmers, 182 00:16:50,410 --> 00:16:53,480 claims to have defeated the Sydney in battle. 183 00:16:55,915 --> 00:16:59,419 Few Australians trust the German captain's account. 184 00:17:00,087 --> 00:17:01,888 He had abandoned his ship, 185 00:17:01,921 --> 00:17:05,392 the Kormoran, which was reportedly nothing more than a cargo vessel, 186 00:17:07,660 --> 00:17:11,464 and there was no evidence of a battle. 187 00:17:11,498 --> 00:17:14,934 The only way to know for sure is to find both ships. 188 00:17:20,006 --> 00:17:23,476 The vessel Geosounder begins a remarkable search off the 189 00:17:23,510 --> 00:17:26,546 coast of Western Australia. 190 00:17:27,614 --> 00:17:31,651 Equipped with new scanning technology and supported by the Australian government 191 00:17:32,485 --> 00:17:37,424 the expedition is led by one of the world's top wreck hunters, David Mearns. 192 00:17:39,592 --> 00:17:42,195 DAVID: The atmosphere was very tense and very pressured. 193 00:17:42,895 --> 00:17:46,032 I had to locate not just one ship, but 2 ships. 194 00:17:47,634 --> 00:17:51,904 NARRATOR: The search area is huge but amazingly the captain of the Kormoran 195 00:17:52,705 --> 00:17:56,709 left an account containing vital clues to where his ship went down. 196 00:18:00,213 --> 00:18:04,151 Mearns homes in on an area 125 miles off the coast. 197 00:18:09,422 --> 00:18:12,892 -Oh yes. -Oh yes. 198 00:18:13,193 --> 00:18:15,061 -This is exactly what you're looking for. 199 00:18:15,094 --> 00:18:18,064 NARRATOR: After 12 days at sea, a sign. 200 00:18:19,466 --> 00:18:21,468 -Here we go. -Here's the rest. 201 00:18:21,868 --> 00:18:23,770 There's the shadow, that's it. 202 00:18:23,803 --> 00:18:26,806 -That's it! -That's it. 203 00:18:29,342 --> 00:18:32,812 NARRATOR: Just as Mearns hoped, by using the captain's account as a guide 204 00:18:33,513 --> 00:18:36,048 he's found the Kormoran. 205 00:18:39,186 --> 00:18:42,289 Is he close to finding the Sydney too? 206 00:18:42,989 --> 00:18:45,192 -Everything all right there. 207 00:18:45,892 --> 00:18:49,629 NARRATOR: Just 4 days later the missing warship comes into view. 208 00:18:51,464 --> 00:18:55,668 -It came up on the screen suddenly and we knew immediately that 209 00:18:55,702 --> 00:18:58,671 was the Sydney. 210 00:18:59,105 --> 00:19:02,709 It was just total elation that we had found it. 211 00:19:04,110 --> 00:19:07,947 We got it. Uh-uh, that's it. That's HMAS Sydney. 212 00:19:14,287 --> 00:19:18,057 NARRATOR: At a depth of 1 and a half miles it's too deep to dive, 213 00:19:18,658 --> 00:19:21,628 so an ROV explores the wreck site. 214 00:19:23,663 --> 00:19:25,398 -There's something. 215 00:19:25,432 --> 00:19:28,134 We're on it, it's a gun, it's hit. 216 00:19:28,435 --> 00:19:30,270 -That's the one? Oh stop, stop right there. 217 00:19:30,303 --> 00:19:33,506 -That's it. -Wow. Oh look at that. 218 00:19:35,208 --> 00:19:39,111 NARRATOR: Among the ruins of a savage fight to the death are chilling reminders 219 00:19:40,012 --> 00:19:43,350 of this ship as a war grave for 645 men. 220 00:19:50,089 --> 00:19:54,494 But the underwater ROV camera only gives us glimpses of the sunken ships. 221 00:19:58,465 --> 00:20:02,201 Now, by combining the scan data with computer generated imagery... 222 00:20:04,637 --> 00:20:08,107 it's possible to drain the Indian Ocean. 223 00:20:10,910 --> 00:20:17,517 This is the HMAS Sydney, the pride of a nation, visible for the first time 224 00:20:18,718 --> 00:20:21,721 in over 70 years. 225 00:20:23,656 --> 00:20:28,661 The warship is pockmarked by battle damage, clear evidence of an epic 226 00:20:28,695 --> 00:20:31,264 close- quarters firefight. 227 00:20:34,133 --> 00:20:39,806 Now using evidence from the seabed, it's possible to reconstruct a remarkable 228 00:20:39,839 --> 00:20:44,911 struggle between the two lost ships and show a Nazi secret weapon in action. 229 00:20:56,689 --> 00:21:01,093 NARRATOR: Draining the Indian Ocean reveals the lost Australian warship, 230 00:21:01,828 --> 00:21:08,701 HMAS Sydney but how did such a powerful vessel fall victim to an ordinary merchant ship? 231 00:21:13,873 --> 00:21:17,410 The Kormoran Captain's account offers some clues. 232 00:21:20,313 --> 00:21:24,016 DETMERS: It was November 19th, 1941. 233 00:21:24,584 --> 00:21:26,986 A beautiful day with warm sunshine. 234 00:21:27,019 --> 00:21:30,623 As so often in the Indian ocean the visibility was perfect. 235 00:21:34,293 --> 00:21:39,298 NARRATOR: Suddenly, at 4:00pm, the two ships eye each other on the horizon, 236 00:21:40,333 --> 00:21:42,869 16 miles apart. 237 00:21:44,003 --> 00:21:49,976 The Kormoran signals that it is an innocent Dutch freighter but as the Sydney moves 238 00:21:50,009 --> 00:21:56,048 in for a closer inspection the Kormoran prepares to unleash its deadly secrets. 239 00:21:58,284 --> 00:22:02,422 The Nazi captain knows his only chance is to lure the warship 240 00:22:02,455 --> 00:22:05,091 into a close-quarters fight. 241 00:22:08,461 --> 00:22:12,031 -I let her come closer still. 242 00:22:12,499 --> 00:22:15,001 Slowly, slowly. 243 00:22:19,271 --> 00:22:22,442 NARRATOR: Then the Kormoran plays its trick. 244 00:22:23,510 --> 00:22:29,516 It appears to be an unarmed merchant vessel but in reality the Nazi ship is packed with 245 00:22:30,417 --> 00:22:34,754 the kind of deadly technology that Q might have created for James Bond. 246 00:22:37,524 --> 00:22:41,528 JANN: The Kormoran's mission in the Indian Ocean was to prey on Allied shipping. 247 00:22:42,829 --> 00:22:46,933 It was very much hit-and-run tactics. 248 00:22:47,233 --> 00:22:51,871 NARRATOR: Unaware of the Kormoran's true identity, the Sydney moves in closer. 249 00:22:54,474 --> 00:22:58,478 DAVID: The two ships were about a 1,000 meters apart, well that's basically 250 00:22:58,511 --> 00:23:00,913 point-blank range. 251 00:23:04,116 --> 00:23:07,854 DETMERS: The enemy cruiser was now coming within the range that I considered 252 00:23:07,887 --> 00:23:10,490 suitable for my guns. 253 00:23:10,723 --> 00:23:13,593 I gave the order, "decamouflage!" 254 00:23:15,595 --> 00:23:18,998 The Dutch flag was hauled down and the German war flag ran up. 255 00:23:20,600 --> 00:23:25,037 NARRATOR: According to the rules of war, concealed weapons are perfectly legal 256 00:23:25,071 --> 00:23:29,876 but only if the ship reveals its true colors before firing. 257 00:23:35,682 --> 00:23:38,918 With the wreck of HMAS Sydney now drained of sea water, 258 00:23:40,620 --> 00:23:45,357 the first shocking evidence caused by Kormoran's hidden weapons can be seen 259 00:23:45,391 --> 00:23:47,994 in the clear light of day. 260 00:23:49,328 --> 00:23:51,564 The top of the captain's bridge, 261 00:23:51,598 --> 00:23:55,502 the command center of the ship is missing, but why? 262 00:24:00,006 --> 00:24:01,641 On the Kormoran, 263 00:24:01,674 --> 00:24:06,212 hidden from view a repurposed army antitank gun emerges 264 00:24:08,715 --> 00:24:12,251 and fires shattering the Australian captain's bridge. 265 00:24:15,522 --> 00:24:19,492 -The command structure of the Sydney would have been wiped out in the first 266 00:24:19,526 --> 00:24:22,428 opening shot of the battle. 267 00:24:23,996 --> 00:24:27,800 NARRATOR: Rapid-fire antiaircraft guns now rise up on hydraulic ramps, 268 00:24:29,101 --> 00:24:31,538 cutting down the Sydney's crew. 269 00:24:35,875 --> 00:24:41,548 On the Sydney's main forward gun turrets the tops have been blown off 270 00:24:44,416 --> 00:24:48,387 and there's a blast hole in the middle of one of the guns. 271 00:24:50,790 --> 00:24:53,660 What causes this? 272 00:24:54,727 --> 00:24:58,865 Despite its innocent appearance the Kormoran carries very heavy weapons, 273 00:24:59,666 --> 00:25:02,034 perfect for close range combat. 274 00:25:03,269 --> 00:25:08,340 At the push of a button, counterweighted panels lift up to reveal these powerful guns. 275 00:25:11,711 --> 00:25:16,515 At virtually point-blank range, their overwhelming firepower knocks out 276 00:25:17,149 --> 00:25:20,086 Sydney's forward gun turrets. 277 00:25:20,787 --> 00:25:24,924 -Well it's probable that those guns were taken out in the first 10 seconds, 278 00:25:25,224 --> 00:25:28,294 15 seconds of the action. 279 00:25:28,795 --> 00:25:33,432 NARRATOR: Although caught by surprise, the Sydney is still able to return fire and 280 00:25:33,465 --> 00:25:36,903 hits the Kormoran's engine room, setting it ablaze. 281 00:25:40,239 --> 00:25:43,109 The Nazi ship now prepares its sledgehammer blow. 282 00:25:46,312 --> 00:25:49,916 Underneath the waterline lie 2 concealed torpedo tubes, 283 00:25:51,083 --> 00:25:54,320 and there are 4 more above the water, 284 00:25:54,587 --> 00:25:57,323 each hidden by a steel flap. 285 00:26:00,660 --> 00:26:06,265 It takes the Kormoran's crew just 32 seconds to prepare and fire a torpedo. 286 00:26:11,303 --> 00:26:14,540 -They inflicted a great deal of damage very quickly on the Australian cruiser. 287 00:26:16,743 --> 00:26:18,577 Guns firing, shells exploding. 288 00:26:18,611 --> 00:26:21,814 I mean it's absolute mayhem, hell on earth. 289 00:26:23,816 --> 00:26:25,652 -They were just being wiped out. 290 00:26:25,685 --> 00:26:28,688 It would have been absolute carnage. 291 00:26:30,690 --> 00:26:33,459 NARRATOR: 6:25 pm. 292 00:26:33,693 --> 00:26:38,030 Confident that the Sydney is fatally wounded and most of the crew already dead, 293 00:26:39,098 --> 00:26:41,901 the Nazi captain ceases fire. 294 00:26:43,703 --> 00:26:45,738 Victory. 295 00:26:48,107 --> 00:26:52,544 DETMERS: Never before in naval history had an armed merchant vessel defeated a cruiser in 296 00:26:53,545 --> 00:26:55,682 open battle. 297 00:26:58,284 --> 00:27:03,055 NARRATOR: Draining the water away from HMAS Sydney, means crucial evidence of what 298 00:27:03,089 --> 00:27:05,792 caused its final death blow can now be seen. 299 00:27:08,294 --> 00:27:11,330 A 90-foot section of its hull is missing. 300 00:27:12,298 --> 00:27:16,302 The Kormoran's torpedoes cause critical damage and a huge explosion. 301 00:27:18,537 --> 00:27:24,510 The Sydney's entire bow breaks off, causing the whole ship to plunge 1 and a half miles down 302 00:27:26,713 --> 00:27:30,683 with 645 men on board. 303 00:27:32,618 --> 00:27:35,688 ERIC: Sydney disappears entirely. 304 00:27:35,922 --> 00:27:38,524 There are no survivors. 305 00:27:39,391 --> 00:27:42,862 It's the most serious loss in the Australian navy's history. 306 00:27:44,263 --> 00:27:48,835 Now we've found the wreck, we know what happened and now we have an accurate idea of what 307 00:27:48,868 --> 00:27:52,104 happened to the ship. 308 00:27:52,504 --> 00:27:56,876 NARRATOR: But if the Sydney was defeated why is the German raider also at the bottom of 309 00:27:56,909 --> 00:27:59,912 the Indian Ocean? 310 00:28:01,147 --> 00:28:04,717 There's a clue in the original scans of the sea floor. 311 00:28:07,186 --> 00:28:11,090 Near the wreck is evidence of a debris field, caused by a massive blast. 312 00:28:13,492 --> 00:28:16,628 What happened to sink the Kormoran? 313 00:28:18,230 --> 00:28:22,401 The Nazi ship sails away victorious but it has been mortally 314 00:28:22,434 --> 00:28:25,004 wounded in the battle. 315 00:28:25,471 --> 00:28:30,609 JANN: With the Kormoran's engines broken down, a huge fire on board and a number of 316 00:28:30,642 --> 00:28:36,415 mines in the hold, which were highly explosive, Commander Detmers had no choice 317 00:28:37,683 --> 00:28:40,486 whatsoever but to abandon ship. 318 00:28:44,056 --> 00:28:47,927 NARRATOR: Hitler has similar merchant raiders, just like the Kormoran. 319 00:28:49,028 --> 00:28:53,665 To stop the ship's many secrets from being discovered the crew then blow up 320 00:28:53,699 --> 00:28:56,235 their own vessel. 321 00:29:00,072 --> 00:29:05,711 Today, the two ships still lie just 13 miles apart on the seabed. 322 00:29:10,649 --> 00:29:14,520 (speaking in German) 323 00:29:14,787 --> 00:29:19,058 The world's oceans hide Nazi secrets deep underwater. 324 00:29:22,261 --> 00:29:24,463 The Baltic Sea. 325 00:29:25,097 --> 00:29:29,301 Draining the icy waters here reveals a forgotten German aircraft carrier 326 00:29:30,269 --> 00:29:34,273 that never saw battle, Graf Zeppelin. 327 00:29:35,942 --> 00:29:39,445 It disappeared more than 70 years ago. 328 00:29:40,312 --> 00:29:44,917 Why is Hitler's only aircraft carrier lying heavily damaged 329 00:29:45,617 --> 00:29:47,920 at the bottom of the Baltic Sea? 330 00:29:54,793 --> 00:29:58,831 NARRATOR: For decades, the ultimate fate of the Nazis' only aircraft carrier is a 331 00:29:59,631 --> 00:30:05,537 mystery but then an oil survey vessel begins scanning the Baltic Sea. 332 00:30:07,539 --> 00:30:11,710 ANDRZEJ: First of all we came across something that piqued our interest. 333 00:30:14,713 --> 00:30:16,916 We found it using a multi-beam sonar. 334 00:30:17,917 --> 00:30:21,320 After post processing the first measurements indicated that it's about 335 00:30:21,687 --> 00:30:24,056 260 meters long. 336 00:30:25,992 --> 00:30:29,428 NARRATOR: It's the largest wreck ever found in the Baltic. 337 00:30:30,897 --> 00:30:35,634 -Wow! It was a really big find. 338 00:30:37,870 --> 00:30:40,306 It was really spectacular. 339 00:30:46,913 --> 00:30:51,550 NARRATOR: Now diver and historian, Stephen Burke is in the Baltic to investigate the 340 00:30:51,583 --> 00:30:55,087 monster of the deep, the Graf Zeppelin. 341 00:30:56,923 --> 00:30:59,758 STEPHEN: When I first learned about the Graf Zeppelin nothing was known as to what 342 00:30:59,791 --> 00:31:02,161 had happened to it at the end of the War. 343 00:31:02,194 --> 00:31:05,464 What happened after that was a complete mystery. 344 00:31:05,497 --> 00:31:10,702 I made it my mission to go out and find what the fate of the ship had been. 345 00:31:14,306 --> 00:31:16,108 NARRATOR: In the darkness, 346 00:31:16,142 --> 00:31:20,879 nearly 290 feet down there are only glimpses of the lost giant. 347 00:31:23,015 --> 00:31:27,319 Timber decking on the flight deck, massive chains from one of the anchors. 348 00:31:32,891 --> 00:31:38,998 At 850 feet long, could its massive size be the very reason why this mighty vessel 349 00:31:40,399 --> 00:31:44,103 never played a full part in the war? 350 00:31:46,638 --> 00:31:50,309 December, 1938. Kiel, Germany. 351 00:31:52,278 --> 00:31:55,747 -Hitler loved launching large warships, he took great pleasure in it, 352 00:31:56,248 --> 00:31:58,517 he saw them as great national symbols. 353 00:31:59,118 --> 00:32:02,688 NARRATOR: Herman Goering, the Head of the Luftwaffe, is master of ceremonies. 354 00:32:12,431 --> 00:32:16,702 NARRATOR: The Nazis had huge ambitions for the vessel. 355 00:32:18,137 --> 00:32:22,641 More than 40 fighters, bombers and torpedo aircraft would have made it a 356 00:32:22,674 --> 00:32:25,077 mighty war machine. 357 00:32:25,311 --> 00:32:29,115 Elevators would carry aircraft from the lower deck up to the flight deck, 358 00:32:30,682 --> 00:32:33,419 planes would launch by catapult. 359 00:32:37,289 --> 00:32:40,026 ERIC: The thought of Stukas taking off from an aircraft carrier, 360 00:32:40,726 --> 00:32:43,662 carrying out torpedo and dive-bombing attacks on allied ships, 361 00:32:43,695 --> 00:32:46,465 it would have greatly strengthened their naval position. 362 00:32:52,238 --> 00:32:55,607 NARRATOR: Winston Churchill sees the Nazi aircraft carrier as a priority target. 363 00:32:58,877 --> 00:33:01,313 -The British were very concerned that the Germans would complete 364 00:33:01,347 --> 00:33:03,315 the Graf Zeppelin. 365 00:33:03,349 --> 00:33:06,018 There was a significant threat. 366 00:33:07,419 --> 00:33:10,122 NARRATOR: But the Nazis are slow to finish this vast warship. 367 00:33:13,425 --> 00:33:17,996 Though launched and sea-worthy, final work is delayed time and time again 368 00:33:19,665 --> 00:33:22,601 because it needs huge amounts of construction material. 369 00:33:24,870 --> 00:33:27,906 -Contrary to appearances Germany was very short of resources. 370 00:33:28,840 --> 00:33:31,310 She was very short of steel. 371 00:33:31,343 --> 00:33:36,782 Because it was thought the War would be short then it was thought that the Graf Zeppelin 372 00:33:36,815 --> 00:33:41,287 might not be complete in time to take part in the war so they had to 373 00:33:41,320 --> 00:33:43,889 stop building large warships. 374 00:33:48,260 --> 00:33:51,263 NARRATOR: February, 1945. 375 00:33:51,297 --> 00:33:54,533 The Nazis face defeat. 376 00:33:55,834 --> 00:34:00,672 -In early 1945 Admiral Doenitz issued a scorched earth policy which was that they were to 377 00:34:00,706 --> 00:34:03,509 destroy certain key assets to prevent them falling into Russian hands, 378 00:34:04,310 --> 00:34:06,712 and one of those assets was the Graf Zeppelin. 379 00:34:09,315 --> 00:34:13,852 NARRATOR: The Graf Zeppelin is scuttled by a German wrecking crew never to see battle, 380 00:34:19,057 --> 00:34:21,893 but that isn't the end of the story. 381 00:34:23,129 --> 00:34:28,800 It was abandoned on the River Oder but now it rests 200 miles away in the 382 00:34:28,834 --> 00:34:31,837 middle of the Baltic. 383 00:34:33,672 --> 00:34:36,942 Why is the Graf Zeppelin here? 384 00:34:40,346 --> 00:34:43,915 After the war, the Russians seize the vast vessel as booty. 385 00:34:47,419 --> 00:34:51,390 -The Russians raised it so they sealed the holes, they pumped the water out and 386 00:34:51,423 --> 00:34:53,725 floated the ship. 387 00:34:55,093 --> 00:34:59,198 NARRATOR: Then they decided to use the Graf Zeppelin for a unique cold war experiment. 388 00:35:02,301 --> 00:35:06,305 Stephen Burke visits the Polish naval academy in Gdynia to investigate. 389 00:35:09,508 --> 00:35:13,111 He's working with former Polish naval officer Adam Olejnik. 390 00:35:14,112 --> 00:35:18,217 ADAM: We have a have a picture, a lot of damage from different military materials. 391 00:35:21,453 --> 00:35:24,823 NARRATOR: Stephen's looking for clues to explain the ship's final moments. 392 00:35:26,024 --> 00:35:28,260 -There's less damage? -Less damage. -Less damage on the port side? 393 00:35:28,294 --> 00:35:30,296 -Less damage, yes. -Okay. 394 00:35:30,329 --> 00:35:34,400 NARRATOR: Adam is part of a Polish Navy team which positively identified 395 00:35:34,433 --> 00:35:36,902 the Graf Zeppelin. 396 00:35:39,338 --> 00:35:41,940 -The enormity of this vessel was a surprise. 397 00:35:44,310 --> 00:35:48,480 It's hard to imagine if you haven't seen it before. 398 00:35:49,114 --> 00:35:52,150 NARRATOR: They used the mapping technology to scan the wreck. 399 00:35:57,122 --> 00:36:02,994 By using the detailed sonar scans now, for the first time in over 70 years, 400 00:36:04,696 --> 00:36:08,300 evidence of the Graf Zeppelin's final moments can be seen. 401 00:36:11,036 --> 00:36:14,906 Emptying the Baltic Sea of water reveals an incredible sight, 402 00:36:17,343 --> 00:36:21,112 the 850-foot-long drowned leviathan. 403 00:36:23,014 --> 00:36:26,918 The wreck clearly shows extensive damage caused by explosives, 404 00:36:29,054 --> 00:36:33,091 including a large 100-foot hole in the deck. 405 00:36:35,394 --> 00:36:37,629 -It looked like the result of bombing. 406 00:36:39,097 --> 00:36:42,601 NARRATOR: The hole wasn't there when the Germans abandoned the ship, 407 00:36:43,302 --> 00:36:45,737 so what caused it? 408 00:36:47,673 --> 00:36:52,678 In August 1947, the Russians want to see how much punishment the Graf Zeppelin 409 00:36:53,312 --> 00:36:56,482 could take before it sinks. 410 00:36:56,748 --> 00:37:01,086 STEPHEN: So they planted a series of bombs inside the wreck, 2,000 kilo 411 00:37:01,119 --> 00:37:03,221 bombs that are detonated on the flight deck. 412 00:37:05,824 --> 00:37:08,994 They then sent in a series of waves of aircraft to attack the ship with bombs, 413 00:37:10,429 --> 00:37:13,299 of over 90 dropped only 5 or 6 hit. 414 00:37:15,334 --> 00:37:19,505 NARRATOR: The Soviets have no aircraft carrier of their own, so by bombing 415 00:37:19,538 --> 00:37:23,809 the Graf Zeppelin they learned a lot about their potential new enemies, 416 00:37:25,143 --> 00:37:28,013 the British and the Americans. 417 00:37:29,214 --> 00:37:33,652 -Sinking the Graf Zeppelin showed the Russians that aircraft carriers were not 418 00:37:33,685 --> 00:37:36,722 necessarily as easy to sink as they might have thought. 419 00:37:39,591 --> 00:37:42,093 They wanted to find out how you sank them, and they did. 420 00:37:46,432 --> 00:37:52,304 (speaking in German) 421 00:37:54,540 --> 00:37:59,478 NARRATOR: Nazi secret technology reached around the world and draining the oceans 422 00:37:59,511 --> 00:38:03,081 reveals evidence of it in the most surprising places. 423 00:38:05,517 --> 00:38:08,053 The English Channel. 424 00:38:08,520 --> 00:38:13,058 The grave of a remarkable vessel equipped with a secret technology that 425 00:38:13,091 --> 00:38:15,694 could have changed the course of the war. 426 00:38:16,595 --> 00:38:21,900 Draining the oceans here reveals the mystery of the Nazi U-boat U-480. 427 00:38:24,102 --> 00:38:27,906 JANN: U-480, you could call it the first stealth submarine in history. 428 00:38:29,908 --> 00:38:35,146 NARRATOR: This vessel vanished in 1945, carrying a lethal secret technology. 429 00:38:36,448 --> 00:38:39,951 What made this killer Nazi sub invisible? 430 00:38:48,494 --> 00:38:51,697 NARRATOR: August, 1944. 431 00:38:52,197 --> 00:38:55,901 The D-day landings in France have put Nazi Germany in peril. 432 00:38:58,937 --> 00:39:02,941 JANN: In August 1944 the situation for the German U-boats in the British Channel 433 00:39:04,042 --> 00:39:10,482 was rather grim because it was one of the best defended areas around the British Isles. 434 00:39:15,621 --> 00:39:18,624 NARRATOR: The Allies have a highly effective method for hunting the 435 00:39:18,657 --> 00:39:22,260 submarine raiders: sonar. 436 00:39:25,230 --> 00:39:29,267 Earlier in the war, the Nazi U-boats savaged Allied shipping in the 437 00:39:29,300 --> 00:39:31,937 Battle of the Atlantic... 438 00:39:33,472 --> 00:39:38,544 largely by hunting in packs on the surface where sonar is of limited use. 439 00:39:41,713 --> 00:39:47,285 But by 1944, heavy surface patrols force the U-boats to operate completely underwater 440 00:39:50,055 --> 00:39:53,859 making them much more vulnerable to Allied sonar. 441 00:39:55,193 --> 00:39:58,464 -This isn't wolf pack warfare against convoys, it's individual submarines 442 00:39:58,497 --> 00:40:00,666 stalking individual ships. 443 00:40:03,902 --> 00:40:07,205 INNES: Operations in a submarine in the English Channel at that time were 444 00:40:07,238 --> 00:40:09,941 extremely dangerous. 445 00:40:10,275 --> 00:40:14,112 Your chances of survival if you're the commander of a U-boat are about 50/50. 446 00:40:14,913 --> 00:40:18,116 NARRATOR: The Nazis want to counter the threat of sonar. 447 00:40:19,284 --> 00:40:25,524 -The German answer to sonar detection was developing some kind of cloak of invisibility. 448 00:40:29,294 --> 00:40:34,199 NARRATOR: By August the 21st, 1944, Hitler's designers have achieved their 449 00:40:34,232 --> 00:40:37,202 dream of stealth technology. 450 00:40:38,103 --> 00:40:42,307 U-boat Captain Hans Joachim Foerster and his crew lie in wait, 451 00:40:43,108 --> 00:40:47,713 deep in the English Channel and the Allies never realize he is there. 452 00:40:52,684 --> 00:40:57,589 -It's unprecedented, he gets into the English Channel and in 5 days he sinks 4 ships, 453 00:41:00,091 --> 00:41:03,061 and he gets out. 454 00:41:03,094 --> 00:41:06,865 It's the most devastating patrol carried out in the Channel up to that time. 455 00:41:08,099 --> 00:41:10,702 It's quite remarkable. 456 00:41:11,002 --> 00:41:15,440 NARRATOR: Will draining the waters of the English Channel help explain this Nazi secret? 457 00:41:19,678 --> 00:41:24,850 Underwater archaeologist Innes McCartney investigates reports of a U-boat wreck 458 00:41:25,483 --> 00:41:30,722 about 20 miles off the coast of Southern England, hidden 200 feet down. 459 00:41:35,026 --> 00:41:38,096 -When you hit the water and you put your hand on the down line and you're swimming down 460 00:41:38,129 --> 00:41:41,499 to the wreck you know the sense of anticipation is, is just truly incredible. 461 00:41:47,505 --> 00:41:52,678 Your first interaction with this completely unseen object is can you work out 462 00:41:52,711 --> 00:41:55,113 what it is? 463 00:41:57,549 --> 00:42:02,554 NARRATOR: Now, for the first time, the waters in the English Channel drain away and 464 00:42:05,090 --> 00:42:09,728 bring U-480 into the clear light of day. 465 00:42:11,429 --> 00:42:15,801 The secret of the stealth submarine is revealed: 466 00:42:16,835 --> 00:42:21,306 the entire surface of the U boat is covered with rubber panels. 467 00:42:24,509 --> 00:42:29,915 Each panel has a series of tiny regular holes, instead of reflecting sonar 468 00:42:30,616 --> 00:42:33,151 signals back to an Allied warship, 469 00:42:33,184 --> 00:42:36,554 these rubber panels absorb them, 470 00:42:36,588 --> 00:42:40,091 making it effectively invisible. 471 00:42:41,526 --> 00:42:45,797 -I put my hand on a, a black rubber panel and I was like, I don't believe 472 00:42:45,831 --> 00:42:48,199 what I've just seen! 473 00:42:50,235 --> 00:42:53,772 ERIC: Diminishing the effectiveness of the other side's sonar could well make 474 00:42:53,805 --> 00:42:55,907 the difference between life and death. 475 00:42:58,009 --> 00:43:03,114 NARRATOR: Today, in Kiel, Germany, one of U480's sister boats still survives. 476 00:43:06,084 --> 00:43:11,589 -U480 wasn't a particularly new design, it was the basic 477 00:43:12,691 --> 00:43:17,996 Type 7 U-boat only covered with this special cloaking device. 478 00:43:20,666 --> 00:43:26,504 NARRATOR: But draining U480 raises another critical question: if it was 479 00:43:27,038 --> 00:43:31,242 undetectable, why is U480 at the bottom of the English Channel? 480 00:43:34,145 --> 00:43:39,550 Removing all the water means that clues to the damage done to U480 can now be revealed. 481 00:43:42,487 --> 00:43:45,523 It has sustained a critical blow. 482 00:43:46,091 --> 00:43:51,196 The stern section is broken off and there's a hole in the pressure hull. 483 00:43:53,064 --> 00:43:56,935 What caused such devastating damage? 484 00:43:59,871 --> 00:44:02,674 Faced with a modern hi-tech threat, 485 00:44:02,708 --> 00:44:06,111 the Allies resort to a very old-fashioned response: 486 00:44:09,447 --> 00:44:11,783 mines. 487 00:44:11,817 --> 00:44:17,188 -The trap that U480 fell victim to was a secret minefield. 488 00:44:20,058 --> 00:44:23,061 NARRATOR: February, 1945. 489 00:44:23,394 --> 00:44:29,067 Shipping lanes crisscross the channel but all Allied vessels are secretly warned not to 490 00:44:30,501 --> 00:44:36,307 travel in a specific shipping lane area and unknown to the U-boat crew, 491 00:44:36,708 --> 00:44:42,080 the British lay what's called a 'deep trap' minefield far below the surface... 492 00:44:44,115 --> 00:44:46,584 Then wait. 493 00:44:46,617 --> 00:44:49,855 -U480 returned to what had been its old hunting grounds, 494 00:44:49,888 --> 00:44:51,990 expecting to find some more targets. 495 00:44:52,023 --> 00:44:54,926 The navigational buoys were there so it seemed as if the route was still being used. 496 00:44:56,327 --> 00:44:58,897 In fact it wasn't. 497 00:44:58,930 --> 00:45:03,034 The British were laying minefields and these came as a very nasty surprise. 498 00:45:05,904 --> 00:45:08,706 -It was laid at the exact point they knew U480 was going. 499 00:45:09,707 --> 00:45:12,878 Targeted killing, based on intelligence. 500 00:45:12,911 --> 00:45:16,414 That's why you keep it secret. 501 00:45:17,916 --> 00:45:20,585 You're blind... 502 00:45:20,618 --> 00:45:23,088 Terrifying. 503 00:45:33,631 --> 00:45:36,101 (explosion) 504 00:45:41,706 --> 00:45:46,111 NARRATOR: 320 pounds of explosive bursts a hole in the submarine, 505 00:45:47,512 --> 00:45:51,482 letting in tons of water per second. 506 00:45:52,383 --> 00:45:56,287 There is no chance of escape. 507 00:45:57,288 --> 00:46:01,259 The secret stealth technology was years ahead of its time, 508 00:46:03,428 --> 00:46:07,665 but in the end even its special cloak of invisibility 509 00:46:07,698 --> 00:46:11,636 could not save U480 from the victorious Allies. 510 00:46:17,909 --> 00:46:20,812 The Nazis lost World War II. 511 00:46:22,347 --> 00:46:26,151 But the deadly secrets they left behind under the world's oceans... 512 00:46:27,185 --> 00:46:31,622 Are a reminder of the extraordinary courage of the men and women who 513 00:46:31,656 --> 00:46:34,192 brought the Nazis down. 514 00:46:41,432 --> 00:46:42,901 Captioned by Cotter Captioning Services.