1 00:00:04,855 --> 00:00:09,057 NARRATOR: Deep beneath the tropical waters of the Gulf of Mexico lies a 2 00:00:09,060 --> 00:00:13,962 seething history of piracy, slavery and bitter conflict. 3 00:00:15,132 --> 00:00:18,233 FRITZ: The Gulf of Mexico was the wild west of the sea and it's every man for himself. 4 00:00:19,704 --> 00:00:25,441 NARRATOR: Imagine if we could empty the oceans, letting the water drain away to reveal 5 00:00:25,542 --> 00:00:27,876 the secrets of the sea floor? 6 00:00:30,848 --> 00:00:33,549 Now we can. 7 00:00:35,453 --> 00:00:40,756 Using the latest underwater scanning technology, piercing the deep oceans and turning 8 00:00:41,391 --> 00:00:45,227 accurate data into 3D images. 9 00:00:47,064 --> 00:00:52,934 This time, why did a deadly German U-Boat end up at the bottom of the ocean off 10 00:00:53,270 --> 00:00:55,170 the coast of New Orleans? 11 00:00:55,172 --> 00:00:58,073 JAMES: Within very short range, the hunter becomes the hunted. 12 00:00:59,210 --> 00:01:03,812 NARRATOR: Who was on board this mysterious wreck, from a time when pirates and 13 00:01:03,814 --> 00:01:06,648 slave traders ruled the waves? 14 00:01:07,118 --> 00:01:11,120 How did a single asteroid impact in the Gulf of Mexico 15 00:01:11,255 --> 00:01:14,422 wipe out the dinosaurs around the globe? 16 00:01:15,092 --> 00:01:18,426 KEN: The base of the food chain is knocked out and things begin to starve. 17 00:01:19,363 --> 00:01:23,632 NARRATOR: And how did drilling for oil result in one of the biggest environmental 18 00:01:23,734 --> 00:01:26,034 disasters in US history? 19 00:01:27,004 --> 00:01:29,938 DAVE: In theory, that well should have been easy. 20 00:01:32,109 --> 00:01:37,713 NARRATOR: Draining the oceans shines new light on the secrets of the Gulf of Mexico. 21 00:01:51,762 --> 00:01:56,331 66 million years ago, dinosaurs roam the Earth. 22 00:01:57,001 --> 00:02:02,237 Then, in a geological instant, they are wiped out, around the planet. 23 00:02:03,907 --> 00:02:07,709 Can draining the water from the Gulf of Mexico explain why? 24 00:02:13,384 --> 00:02:18,921 The story begins not in the Gulf but over 1,500 miles away in New Jersey. 25 00:02:21,124 --> 00:02:25,894 This former quarry is one of the most important fossil sites in the world, 26 00:02:25,996 --> 00:02:30,932 because here, paleontologists discover a mass prehistoric graveyard. 27 00:02:32,036 --> 00:02:37,105 -This is the boundary between the cretaceous period, the age of the dinosaurs and 28 00:02:37,207 --> 00:02:39,208 the age that comes after that, the Paleogene. 29 00:02:39,309 --> 00:02:44,746 And what we have here is a bone bed, where we have about 25 fossils per square meter. 30 00:02:45,416 --> 00:02:51,253 Paleontologists have never found an in-place dinosaur bone one centimeter above that 31 00:02:51,889 --> 00:02:54,589 extinction layer anywhere on the planet. 32 00:02:54,792 --> 00:02:59,261 NARRATOR: The absence of dinosaur fossils above this layer can mean only one thing. 33 00:02:59,697 --> 00:03:01,930 They were wiped out by a sudden, 34 00:03:01,932 --> 00:03:05,000 cataclysmic event, 66 million years ago. 35 00:03:05,635 --> 00:03:10,472 -Whatever took out the dinosaurs was global, terrible and instantaneous. 36 00:03:11,642 --> 00:03:14,142 NARRATOR: Experts have offered many answers. 37 00:03:14,244 --> 00:03:16,812 But only one is widely accepted. 38 00:03:16,947 --> 00:03:21,350 -By far the leading explanation is that an asteroid hit the earth 39 00:03:21,451 --> 00:03:25,621 66 million years ago and unleashed hell on earth and took out the dinosaurs 40 00:03:25,756 --> 00:03:28,856 and 75% of life. 41 00:03:29,059 --> 00:03:31,226 NARRATOR: Scientists scour the planet. 42 00:03:31,328 --> 00:03:34,296 Looking for evidence of asteroid strikes. 43 00:03:39,036 --> 00:03:43,839 But none of the impact craters that they find are big enough and of the right 44 00:03:43,841 --> 00:03:46,575 age to be the culprit. 45 00:03:47,044 --> 00:03:51,813 Then, in Mexico's Yucatan peninsula, they find a surprising lead. 46 00:03:55,686 --> 00:04:00,522 Mario Rebolledo, is an expert in a remarkable natural phenomenon found all 47 00:04:00,624 --> 00:04:02,591 over this region. 48 00:04:02,693 --> 00:04:06,495 Sinkholes, known locally as cenotes, 49 00:04:09,499 --> 00:04:12,066 formed by the erosion of soft limestone, 50 00:04:12,069 --> 00:04:15,270 they can be hundreds of feet deep. 51 00:04:16,407 --> 00:04:19,341 Exploring them requires years of experience. 52 00:04:40,297 --> 00:04:44,032 NARRATOR: Mario discovers that many of the cenotes are linked through deep, 53 00:04:44,101 --> 00:04:46,868 subterranean channels. 54 00:04:49,106 --> 00:04:51,006 But that's not all. 55 00:04:51,008 --> 00:04:53,508 They also display a remarkably similar structure. 56 00:05:18,502 --> 00:05:22,971 NARRATOR: When seen from above, an extraordinary picture begins to emerge. 57 00:05:23,907 --> 00:05:26,775 The cenotes form an outline. 58 00:05:28,145 --> 00:05:31,813 It looks like the rim of a gigantic crater. 59 00:05:32,015 --> 00:05:37,486 The most likely explanation is that a massive asteroid strike reshaped this region and then 60 00:05:37,988 --> 00:05:41,622 the sinkholes formed in fault lines around its edge. 61 00:05:42,058 --> 00:05:46,360 Could this be the crater that's linked to the death of the dinosaurs? 62 00:05:46,696 --> 00:05:52,900 Today, millions of years after it was created, the heart of the impact site lies concealed 63 00:05:52,903 --> 00:05:58,040 not just under the waters of the Gulf of Mexico, but under several thousand feet of 64 00:05:58,175 --> 00:06:00,508 sedimentary rock. 65 00:06:00,677 --> 00:06:06,381 The only way to calculate its age and see if it dates from the demise of the dinosaurs is 66 00:06:06,383 --> 00:06:09,651 to analyze rocks from the crater itself. 67 00:06:11,455 --> 00:06:15,756 SEAN: To really understand impact cratering we actually need to pull rocks 68 00:06:15,793 --> 00:06:17,826 from ground zero. 69 00:06:17,894 --> 00:06:21,896 We need to find a place where we know that the damage has been the greatest in 70 00:06:22,533 --> 00:06:25,867 order to get a sense of the way impact craters work. 71 00:06:28,405 --> 00:06:33,141 NARRATOR: In 2016, an international team of scientists drill down from 72 00:06:33,143 --> 00:06:35,944 this specially adapted oil platform. 73 00:06:36,680 --> 00:06:40,281 SEAN: And so, we were pulling up limestone after limestone after limestone. 74 00:06:40,317 --> 00:06:42,750 We're getting ages from the fossils within them. 75 00:06:42,852 --> 00:06:46,988 We know we are at 48 or 50 million years but we're not yet at 66, right. 76 00:06:47,391 --> 00:06:50,358 And then things suddenly jumped in time. 77 00:06:50,360 --> 00:06:54,563 NARRATOR: The team hits a layer of melted rock, indicating an asteroid strike. 78 00:06:55,398 --> 00:06:59,668 And samples confirm that the rocks are 66 million years old, 79 00:07:00,070 --> 00:07:03,105 the exact moment when the dinosaurs died. 80 00:07:05,142 --> 00:07:09,878 Next, the team analyze the rocks to calculate the asteroid's power 81 00:07:12,616 --> 00:07:17,452 comparing their data to that generated by nuclear bomb tests. 82 00:07:19,356 --> 00:07:23,591 -And we can come up with an estimate of the amount of energy released and that turns 83 00:07:23,693 --> 00:07:26,428 out to be about ten billion Hiroshima's. 84 00:07:32,803 --> 00:07:36,471 NARRATOR: Using this data, it's possible, for the very first time, 85 00:07:36,539 --> 00:07:43,144 to create a 3D visualization of the crater, now hidden deep beneath the Earth and discover 86 00:07:43,880 --> 00:07:48,150 how a single asteroid impact in the Gulf of Mexico could wipe out 87 00:07:48,251 --> 00:07:51,119 dinosaurs around the globe. 88 00:07:52,156 --> 00:07:55,957 First, the entire Gulf must be drained away. 89 00:07:56,026 --> 00:08:00,428 As the water recedes, it reveals a vast continental shelf running 90 00:08:00,430 --> 00:08:02,630 around the coastline. 91 00:08:02,732 --> 00:08:07,702 The crumpled plain is thick with sediment, but the crater is still hidden under 92 00:08:07,738 --> 00:08:10,238 thousands of feet of rock. 93 00:08:11,441 --> 00:08:17,812 66 million years of geology must now be rolled back, draining away layer upon layer 94 00:08:18,615 --> 00:08:25,053 of sedimentary rock, until the impact site begins to emerge, a sight that no living 95 00:08:25,055 --> 00:08:29,290 creature has witnessed for 66 million years. 96 00:08:29,760 --> 00:08:32,794 The crater is immense. 97 00:08:32,796 --> 00:08:36,898 Over half a mile deep and 120 miles wide. 98 00:08:37,234 --> 00:08:41,802 Around its edge towers the outer rim, formed by rock ejected from deep 99 00:08:41,805 --> 00:08:44,372 within the Earth's crust. 100 00:08:44,441 --> 00:08:49,144 Now, by studying the crater's profile, it's possible to determine the size and speed 101 00:08:49,279 --> 00:08:51,346 of the asteroid. 102 00:08:51,348 --> 00:08:56,218 It's over 7 miles wide and it travels at 40,000 miles per hour. 103 00:08:57,887 --> 00:09:01,289 And the crater's dimensions tell us something else. 104 00:09:01,291 --> 00:09:05,026 30,000 cubic miles of rock are displaced here. 105 00:09:05,095 --> 00:09:10,365 Vast amounts hurled into the atmosphere, setting off a devastating chain of events. 106 00:09:13,270 --> 00:09:17,938 -It blows a hole in the ground about the size of the State of Massachusetts. 107 00:09:18,308 --> 00:09:22,043 Now all that rock, it gets pulverized, thrown up through the earth's atmosphere. 108 00:09:22,545 --> 00:09:26,014 It starts to orbit the planet and when that rock comes back in, 109 00:09:26,316 --> 00:09:29,317 it's got a tremendous amount potential gravitational energy. 110 00:09:29,419 --> 00:09:33,388 it heats up the atmosphere to toaster oven or pizza oven temperatures, 111 00:09:33,489 --> 00:09:36,524 frying everything that doesn't have a place to hide. 112 00:09:37,293 --> 00:09:41,363 NARRATOR: Almost every living creature within 600 miles is killed by 113 00:09:41,365 --> 00:09:43,331 this deadly fireball. 114 00:09:43,367 --> 00:09:46,434 But those further away do not escape. 115 00:09:46,703 --> 00:09:50,005 -Later that day the tsunami waves wash up on the shore. 116 00:09:50,106 --> 00:09:53,875 These could have been hundreds of feet tall, maybe even half a mile tall when they hit 117 00:09:53,944 --> 00:09:57,078 here, and they would have run up through the continent. 118 00:09:57,114 --> 00:10:00,147 Animals that are still alive would have heard the wave coming for them 119 00:10:00,150 --> 00:10:02,751 but wouldn't have seen it in the darkness. 120 00:10:02,819 --> 00:10:06,354 NARRATOR: But the asteroid strike becomes a truly global disaster for 121 00:10:06,356 --> 00:10:08,690 one specific reason... 122 00:10:08,791 --> 00:10:11,392 where it hits Earth. 123 00:10:11,895 --> 00:10:15,363 This part of the planet contains rocks high in Sulphur. 124 00:10:15,399 --> 00:10:19,768 On impact, the Sulphur is vaporized and blasted high above the Earth. 125 00:10:20,437 --> 00:10:23,971 -Well that Sulphur combines with the atmosphere and becomes sulphate aerosols and 126 00:10:24,073 --> 00:10:27,809 sulphate aerosols are excellent at blocking sunlight. 127 00:10:27,944 --> 00:10:32,747 NARRATOR: This deadly cloud shrouds the planet and the Earth begins to cool. 128 00:10:34,584 --> 00:10:39,653 By studying the crater in more detail it's possible to see new evidence of how the 129 00:10:39,690 --> 00:10:43,458 crater's shape makes the Sulphur cloud even more deadly. 130 00:10:44,761 --> 00:10:47,061 The north-east rim is open. 131 00:10:47,063 --> 00:10:51,665 The asteroid hits deep water here absorbing some of the impact and 132 00:10:51,668 --> 00:10:55,270 thirty minutes later the ocean rushes back in. 133 00:10:56,473 --> 00:11:00,475 Water vapor from this tsunami combines with the Sulphur to form 134 00:11:00,576 --> 00:11:04,178 sunlight- blocking gases in even larger quantities. 135 00:11:05,415 --> 00:11:09,350 -The plankton in the ocean can't do photosynthesis and pretty soon the base of the 136 00:11:09,452 --> 00:11:12,487 food chain is knocked out and things begin to starve. 137 00:11:14,624 --> 00:11:19,160 NARRATOR: Lack of sunlight means the entire planet experiences an average cooling 138 00:11:19,162 --> 00:11:22,897 of 47 degrees Fahrenheit for up to 16 years. 139 00:11:24,835 --> 00:11:28,569 Only the toughest plants and animals survive. 140 00:11:28,638 --> 00:11:31,239 The dinosaurs do not. 141 00:11:31,942 --> 00:11:37,378 One question remains, was this event unique or could it happen again, 142 00:11:37,747 --> 00:11:40,648 this time wiping out human-kind? 143 00:11:41,317 --> 00:11:45,453 -There are other near-Earth objects out there, asteroids just like the one that took 144 00:11:45,555 --> 00:11:48,990 out the dinosaurs and we do not know where they all are. 145 00:11:49,091 --> 00:11:53,127 Every day, scientists are discovering more and more asteroids that have the power 146 00:11:53,130 --> 00:11:55,563 to menace our earth. 147 00:11:58,234 --> 00:12:00,535 SEAN: Now, we think we've tracked all the big ones. 148 00:12:00,637 --> 00:12:03,805 So, we don't think there is another event that is just around the corner, 149 00:12:03,807 --> 00:12:09,077 but that doesn't mean we shouldn't keep making sure, given the circumstances. 150 00:12:09,979 --> 00:12:14,682 NARRATOR: As we drain the Gulf of Mexico further, it's possible to reveal areas 151 00:12:14,684 --> 00:12:18,352 where humans are drilling thousands of feet below the sea bed 152 00:12:18,454 --> 00:12:23,258 to exploit a natural resource formed 100 million years ago... 153 00:12:24,627 --> 00:12:26,827 oil. 154 00:12:26,830 --> 00:12:31,466 But how did a failure while drilling in the Gulf of Mexico turn into the biggest oil 155 00:12:31,468 --> 00:12:33,902 spill in US history? 156 00:12:37,874 --> 00:12:41,142 NARRATOR: The economy of the Gulf of Mexico is driven by oil. 157 00:12:42,579 --> 00:12:48,983 This vast, oil rich basin accounts for 17% of total US crude oil production. 158 00:12:50,020 --> 00:12:55,189 Nearly half of America's oil refining capacity sits along the Gulf coast. 159 00:12:56,026 --> 00:13:00,662 But it's offshore that the scale of the infrastructure needed to bring oil to the 160 00:13:00,664 --> 00:13:03,898 surface is truly staggering. 161 00:13:06,135 --> 00:13:11,205 Using the latest data and visualization techniques, draining away the waters of 162 00:13:11,207 --> 00:13:15,510 the Gulf of Mexico exposes an extraordinary underwater world, 163 00:13:16,413 --> 00:13:20,114 normally hidden in the dark depths of the ocean. 164 00:13:21,317 --> 00:13:26,621 But how did an accident here cause the worst environmental disaster in the history of the 165 00:13:26,690 --> 00:13:28,857 Gulf of Mexico? 166 00:13:31,895 --> 00:13:37,198 Pumpjacks like these, introduced in the 1920s, can only extract oil in very small 167 00:13:37,833 --> 00:13:40,434 quantities, on land. 168 00:13:40,637 --> 00:13:45,373 DAVE: An old well like this is perhaps producing only 10 barrels per day of oil. 169 00:13:47,143 --> 00:13:49,711 This is old technology. 170 00:13:49,812 --> 00:13:52,313 This is on the twilight of an oil field. 171 00:13:52,382 --> 00:13:55,116 You can tell that because it's nodding up and down. 172 00:13:55,217 --> 00:13:58,987 That means that the pressure in that reservoir down there is low. 173 00:13:59,221 --> 00:14:01,656 It's about ready to be finished. 174 00:14:01,892 --> 00:14:06,727 NARRATOR: In the 1940s, oil companies discover a far more productive source, 175 00:14:06,796 --> 00:14:09,797 below the waters of the Gulf of Mexico. 176 00:14:10,433 --> 00:14:13,000 Here, the oil doesn't need to be pumped. 177 00:14:13,069 --> 00:14:14,936 It flows. 178 00:14:15,005 --> 00:14:19,073 And the reason lies deeply embedded in the unique geology of the Gulf. 179 00:14:19,642 --> 00:14:24,012 JAMES: The Gulf of Mexico is one of the more oil rich areas on the planet because out beyond 180 00:14:24,014 --> 00:14:27,215 us was once an ancient swamp 300 million years ago. 181 00:14:29,085 --> 00:14:32,687 That swamp now is not only under the water, it's underneath the earth. 182 00:14:32,789 --> 00:14:36,925 And as a result of pressure and heat all of that organic material has been 183 00:14:36,993 --> 00:14:39,694 transformed into oil. 184 00:14:39,729 --> 00:14:43,464 NARRATOR: To produce an oil field, three things are essential. 185 00:14:43,566 --> 00:14:46,768 A layer of kerogen, the organic compound which creates oil. 186 00:14:47,870 --> 00:14:52,573 A permeable rock such as sandstone known as 'source rock' for the oil 187 00:14:52,943 --> 00:14:54,976 to accumulate in. 188 00:14:55,011 --> 00:14:59,913 And a trap: a layer of impermeable rock above, to prevent the oil dissipating. 189 00:15:00,650 --> 00:15:05,586 By drilling down through this hard layer, it's possible to extract the oil and gas from 190 00:15:05,789 --> 00:15:07,989 the reservoir below. 191 00:15:08,158 --> 00:15:11,592 And the Gulf's continental shelf provides the perfect base for 192 00:15:11,694 --> 00:15:14,395 offshore drilling platforms. 193 00:15:15,598 --> 00:15:19,667 -When you look out over the Gulf of Mexico and you see this flat expanse of water, 194 00:15:19,769 --> 00:15:22,670 most people don't realize that this is very shallow. 195 00:15:22,672 --> 00:15:27,708 You can go 50 to 100 miles out but it's only 100 feet deep. 196 00:15:28,478 --> 00:15:32,079 NARRATOR: Since the first platform was constructed just a mile offshore, 197 00:15:32,115 --> 00:15:34,882 the network has expanded greatly. 198 00:15:34,884 --> 00:15:38,886 Around 3,500 platforms now sit off the coast. 199 00:15:40,823 --> 00:15:45,359 But it's only by draining the ocean that it's possible to see the sheer scale of the 200 00:15:45,428 --> 00:15:48,095 infrastructure hidden beneath the waves. 201 00:15:48,864 --> 00:15:53,167 As the water recedes, these huge structures are left high and dry. 202 00:15:54,504 --> 00:15:59,040 There are more oil platforms here than in the rest of the world combined. 203 00:16:00,643 --> 00:16:06,214 In the 1970s companies begin to move off the continental shelf into ever deeper waters 204 00:16:06,816 --> 00:16:10,017 to tap into even bigger reserves. 205 00:16:10,119 --> 00:16:15,323 Operating in the Gulf's very deepest regions, up to 10,000 feet below the waves, 206 00:16:15,425 --> 00:16:18,526 where conditions are extremely hostile. 207 00:16:20,262 --> 00:16:22,262 DAVE: It is completely black. 208 00:16:22,265 --> 00:16:25,933 Temperature down there is just above freezing. 209 00:16:26,836 --> 00:16:32,106 You're drilling another sometimes 20,000 feet below the seabed and it gets 210 00:16:32,108 --> 00:16:34,242 extremely hot. 211 00:16:34,343 --> 00:16:38,446 So you have this big contrast between something that's very hot to something that's very 212 00:16:38,448 --> 00:16:41,649 cold, let alone the extremely high pressures that we have. 213 00:16:42,952 --> 00:16:46,954 NARRATOR: Today, there are around 50 deep-water rigs sited in the Gulf. 214 00:16:49,391 --> 00:16:55,296 Continuing to drain its waters beyond the continental shelf reveals the huge scale of 215 00:16:55,765 --> 00:17:00,501 infrastructure needed to bring oil to the surface from these super-deep wells. 216 00:17:01,971 --> 00:17:07,041 Clusters of well-heads control the flow of oil and gas from deep below the sea bed. 217 00:17:07,577 --> 00:17:11,879 The pressure in the wells can reach up to 22,000 pounds per square inch. 218 00:17:14,150 --> 00:17:18,920 The well-heads connect to a central manifold, up to 100 feet high, 219 00:17:18,988 --> 00:17:22,723 which controls the flow of oil and gas from across the oil field up 220 00:17:22,759 --> 00:17:25,125 to the production rig. 221 00:17:25,128 --> 00:17:31,132 The rig separates the oil and gas before they're transported to shore by pipeline some 222 00:17:31,201 --> 00:17:35,203 stretching for hundreds of miles as they wind their way along the sea bed. 223 00:17:36,639 --> 00:17:41,976 An incredible 43,000 miles of pipeline snakes across the floor of the Gulf. 224 00:17:44,247 --> 00:17:48,882 With oil reserves close to shore now becoming depleted, companies continue to search 225 00:17:48,885 --> 00:17:53,221 the Gulf of Mexico for new, more productive oil fields. 226 00:17:53,556 --> 00:17:58,092 Special rigs, costing nearly half a million dollars a day to operate, 227 00:17:58,528 --> 00:18:03,798 drill exploration wells called wildcats, reaching miles below the sea bed. 228 00:18:04,500 --> 00:18:08,402 One such rig is called the Deepwater Horizon. 229 00:18:08,938 --> 00:18:12,840 DAVE: The Deepwater Horizon is an exploration drilling rig. 230 00:18:12,842 --> 00:18:18,412 We use what we call mobile drilling units to come in and drill the initial well. 231 00:18:19,582 --> 00:18:25,386 If we find oil we run casing down there we cement it off and then we move that 232 00:18:25,388 --> 00:18:30,791 exploration rig off location and then come back later to put on 233 00:18:30,827 --> 00:18:32,993 the production equipment. 234 00:18:33,963 --> 00:18:38,733 NARRATOR: In 2010, the Deepwater Horizon strikes oil 50 miles off the coast of 235 00:18:38,735 --> 00:18:41,936 Louisiana in an area codenamed Macondo. 236 00:18:42,838 --> 00:18:48,609 -In theory that well should have been easy in that the water depth 237 00:18:49,145 --> 00:18:50,811 about 5000 feet. 238 00:18:50,880 --> 00:18:54,582 We have been drilling in 5000 feet of water since 1979. 239 00:18:55,084 --> 00:18:57,551 The pressure wasn't too high either. 240 00:18:57,653 --> 00:19:01,589 However, we are in a very potentially dangerous industry. 241 00:19:06,696 --> 00:19:09,697 REPORTER (over TV): Now another major story developing in the Gulf of Mexico. 242 00:19:09,699 --> 00:19:14,035 Eleven people are missing after an explosion and fire on an off-shore oil rig. 243 00:19:14,771 --> 00:19:17,972 REPORTER 2 (over TV): The explosion happened aboard a mobile offshore 244 00:19:18,041 --> 00:19:19,573 drilling unit called the Deepwater Horizon. 245 00:19:19,575 --> 00:19:23,611 It erupted with 126 people on board. 246 00:19:23,646 --> 00:19:28,115 NARRATOR: The cement lining, designed to seal the well before the rig moves away, 247 00:19:28,217 --> 00:19:32,987 has a leak in it allowing oil and gas to force their way up to the rig and ignite. 248 00:19:35,358 --> 00:19:37,959 After burning for two days, the rig sinks. 249 00:19:39,996 --> 00:19:43,197 The eleven missing workers are never found. 250 00:19:45,368 --> 00:19:51,038 In the aftermath, 60,000 barrels of oil per day escape into the Gulf. 251 00:19:54,310 --> 00:19:58,479 With the well-head a mile underwater and the oil pressure so high, 252 00:19:58,514 --> 00:20:01,548 engineers can't stop the flow. 253 00:20:03,086 --> 00:20:09,022 -In the immediate aftermath of the disaster even while the well was flowing the 254 00:20:09,025 --> 00:20:14,761 government stopped all deep-water drilling in the Gulf of Mexico and rightly so 255 00:20:14,764 --> 00:20:20,734 until we could figure out what had happened and what you need to do to be sure not only it 256 00:20:21,104 --> 00:20:24,972 doesn't happen again but if it does happen that you have equipment so 257 00:20:25,074 --> 00:20:27,942 that you can stop it immediately. 258 00:20:28,944 --> 00:20:33,881 NARRATOR: To seal the Macondo well, engineers design a solution from scratch... 259 00:20:34,250 --> 00:20:38,986 a capping stack to latch over the well-head, working remotely at incredible depths. 260 00:20:40,723 --> 00:20:47,194 By the time the well is sealed 87 days after the blowout, nearly 5 million barrels of 261 00:20:47,263 --> 00:20:50,797 crude oil have escaped. 262 00:20:51,301 --> 00:20:55,503 The worst environmental disaster ever to strike the Gulf of Mexico. 263 00:20:59,542 --> 00:21:03,144 The wreck of the Deepwater Horizon now lies on the sea bed. 264 00:21:05,381 --> 00:21:07,481 But it's not alone. 265 00:21:07,583 --> 00:21:12,019 Human commerce began in the Gulf of Mexico hundreds of years before the oil and gas 266 00:21:12,121 --> 00:21:14,521 industry took hold. 267 00:21:14,524 --> 00:21:19,493 As the water continues to drain away, an extraordinary relic of the region's maritime 268 00:21:19,928 --> 00:21:24,899 history is about to be revealed from a time when the Gulf became a superhighway for 269 00:21:25,969 --> 00:21:30,204 pirates and smugglers trading in the most valuable 'commodity' of the age... 270 00:21:30,840 --> 00:21:32,640 human life. 271 00:21:36,712 --> 00:21:40,481 NARRATOR: Oil and gas exploration means the seabed of the Gulf of Mexico is 272 00:21:40,550 --> 00:21:43,184 surveyed in fine detail. 273 00:21:48,424 --> 00:21:53,427 And the search for oil regularly uncovers long-lost shipwrecks. 274 00:21:54,463 --> 00:21:59,467 Including a mysterious ship 150 miles south of New Orleans. 275 00:22:02,171 --> 00:22:05,639 As the water of the Gulf of Mexico continues to drain away, 276 00:22:06,042 --> 00:22:10,177 it will be exposed to the sky for the first time in 200 years, 277 00:22:11,047 --> 00:22:15,749 giving an extraordinary insight into a period renowned for piracy, 278 00:22:15,852 --> 00:22:18,452 smuggling and slavery. 279 00:22:19,155 --> 00:22:23,657 Who was on this mysterious ship and what was its cargo? 280 00:22:27,063 --> 00:22:30,597 Sitting at the mouth of the great Mississippi River, New Orleans, 281 00:22:30,600 --> 00:22:34,401 in the early 19th century, expands rapidly. 282 00:22:35,071 --> 00:22:37,671 FREDERICK: New Orleans was basically a bustling maritime entrepôt. 283 00:22:37,673 --> 00:22:40,875 I mean, this was one of the largest ports in the western hemisphere and 284 00:22:40,877 --> 00:22:43,677 it was situated centrally in the Gulf of Mexico. 285 00:22:43,713 --> 00:22:47,080 And so, you have hundreds of ships coming and going, importing, 286 00:22:47,182 --> 00:22:49,283 exporting all sorts of different kinds of trade goods, 287 00:22:49,285 --> 00:22:54,288 but you're also seeing an increase in illicit activity from slave trade to smuggling, 288 00:22:55,057 --> 00:22:58,025 and, and this place is just booming. 289 00:22:58,327 --> 00:23:02,229 NARRATOR: Hard evidence of this extraordinary period of maritime history 290 00:23:02,265 --> 00:23:04,098 is extremely rare. 291 00:23:06,302 --> 00:23:11,905 Then, in 2011, an oil company identifies a wreck, giving it the name 'The Monterrey'. 292 00:23:13,342 --> 00:23:15,509 FREDRICK: This particular shipwreck lies on the sea floor at an approximate 293 00:23:15,511 --> 00:23:17,978 depth of 4500 feet or almost a mile, 294 00:23:18,614 --> 00:23:22,583 which makes it really difficult to get to, but it also means it's going 295 00:23:22,684 --> 00:23:25,652 to be that much better preserved because the temperature at that depth is 296 00:23:25,688 --> 00:23:28,856 four degrees Celsius and that really slows the rate of decomposition. 297 00:23:30,393 --> 00:23:34,461 NARRATOR: The team launch a state of the art remotely operated vehicle, 298 00:23:34,530 --> 00:23:36,797 or ROV, to investigate. 299 00:23:37,500 --> 00:23:39,934 FREDRICK: The ROV takes four hours to get down to the sea floor 300 00:23:40,035 --> 00:23:43,537 and so, you know, there's this anticipation. 301 00:23:45,741 --> 00:23:50,944 When the ROV hits the floor and cruises up to this particular site and we lay our 302 00:23:50,980 --> 00:23:54,882 eyes on the shipwreck for the first time, we're astounded, we're excited. 303 00:23:56,051 --> 00:24:00,354 Because what we're looking at is a largely intact ship almost a mile deep in the 304 00:24:00,356 --> 00:24:04,224 Gulf of Mexico and it was just mind-blowing. 305 00:24:04,694 --> 00:24:09,630 NARRATOR: As the ROV travels over the wreck it sends back tantalizing glimpses 306 00:24:09,699 --> 00:24:12,165 of the ship and its contents. 307 00:24:12,301 --> 00:24:15,435 -At this depth in the ocean it's pitch black, there's no light, 308 00:24:15,537 --> 00:24:18,105 you can't see anything unless you light it up. 309 00:24:18,107 --> 00:24:23,511 So, when we're working on sites like this in particular, we're only getting snapshots 310 00:24:24,313 --> 00:24:27,581 or small glimpses of the site itself. 311 00:24:27,917 --> 00:24:31,619 We don't have the entire picture while we're viewing the ROV footage. 312 00:24:34,690 --> 00:24:38,893 NARRATOR: The ROV also captures precise data from on-board sonar equipment. 313 00:24:41,497 --> 00:24:46,667 Combining this with the latest visualization techniques, it's now possible to drain 314 00:24:46,702 --> 00:24:53,273 the ocean and pull the plug on more of the Gulf of Mexico, letting archaeologists view 315 00:24:53,275 --> 00:24:57,578 the wreck from any angle and examine it in unexpected detail. 316 00:24:59,181 --> 00:25:05,218 Will seeing it for the first time in 200 years help them discover what it was doing, 317 00:25:05,254 --> 00:25:10,824 how it came to lie on the sea bed and the biggest mystery of all: who was on board. 318 00:25:12,828 --> 00:25:16,563 As the water recedes, the ship is revealed. 319 00:25:17,399 --> 00:25:20,233 The bow, sheathed in copper to protect against 320 00:25:20,236 --> 00:25:25,139 marine organisms, still intact and the anchor still stowed. 321 00:25:27,910 --> 00:25:33,213 Chain plates, once used to secure the rigging, indicate it had two wooden masts, 322 00:25:34,282 --> 00:25:37,050 long lost to the ocean. 323 00:25:37,253 --> 00:25:42,188 With the water gone, six cannon lay exposed to the sky. 324 00:25:42,525 --> 00:25:47,228 And around the stern, lying on the sea floor, a cache of muskets. 325 00:25:53,836 --> 00:25:57,737 JAMES: What struck me was this was a ship that was very long and narrow 326 00:25:58,107 --> 00:26:00,107 particularly at the bow. 327 00:26:00,109 --> 00:26:03,610 It struck me as almost being like a clipper ship, a specific type of vessel that 328 00:26:03,679 --> 00:26:07,448 came into the fore really in the early 1800s. 329 00:26:08,917 --> 00:26:12,085 NARRATOR: Clippers were perfectly suited to the Gulf of Mexico due to 330 00:26:12,187 --> 00:26:13,987 their shallow draft, 331 00:26:14,090 --> 00:26:17,757 ideal for navigating the Gulf's coastal waters and marshy bayou. 332 00:26:18,628 --> 00:26:20,961 -What also struck us was that it was armed. 333 00:26:21,063 --> 00:26:25,199 It had cannon, and there were muskets, was it a warship, was it something else? 334 00:26:26,135 --> 00:26:28,568 NARRATOR: Is it a privateer? 335 00:26:28,571 --> 00:26:32,573 -A privateer is basically an individual that has written permission or letter of marque 336 00:26:32,641 --> 00:26:38,312 or letter of commission from a respective government giving them permissions to capture 337 00:26:38,414 --> 00:26:43,884 ships, to make incursions on enemy soil in the name of that particular country. 338 00:26:44,553 --> 00:26:49,189 -Privateering is basically state sponsored piracy, in which the privateer gets a cut 339 00:26:49,291 --> 00:26:52,159 of the action and the rest goes to the state that's licensed them. 340 00:26:53,863 --> 00:26:57,864 NARRATOR: In the first two decades of the 19th century there are hundreds 341 00:26:57,933 --> 00:27:00,534 of privateers in the Gulf of Mexico. 342 00:27:01,270 --> 00:27:05,672 But as the ocean drains even further away from around the Monterrey, 343 00:27:06,074 --> 00:27:08,475 there's a twist to this story. 344 00:27:08,477 --> 00:27:11,010 The wreck is not alone. 345 00:27:11,613 --> 00:27:17,017 As the water disappears, a complete picture of the entire sea floor begins to emerge for 346 00:27:17,119 --> 00:27:20,821 the very first time, revealing the remains of two other ships, 347 00:27:22,124 --> 00:27:24,825 each containing further clues. 348 00:27:24,827 --> 00:27:29,163 -It's really exciting to have one shipwreck but when all of a sudden you go from one to 349 00:27:29,564 --> 00:27:34,701 three it gets incrementally more exciting because now we're not talking about just 350 00:27:34,803 --> 00:27:37,905 one wreck we're talking about a potential convoy. 351 00:27:38,941 --> 00:27:43,810 NARRATOR: Wreck A, the first ship discovered, is heavily armed with cannon and muskets 352 00:27:44,346 --> 00:27:49,182 for close quarter combat, leaving researchers to think it could be a privateer. 353 00:27:49,985 --> 00:27:54,488 With wreck B, it's clear that the wooden hull has been consumed by the ocean. 354 00:27:56,158 --> 00:27:59,660 But its cargo is still intact. 355 00:27:59,828 --> 00:28:05,132 It's carrying animal hides, a valuable commodity at the time and frequently traded. 356 00:28:05,935 --> 00:28:11,104 Treated and rolled for shipment, they are well preserved by the cold waters. 357 00:28:11,540 --> 00:28:16,944 Wreck C, exposed to the sky for the first time in 200 years, is a larger, 358 00:28:17,079 --> 00:28:18,879 three-masted vessel. 359 00:28:18,981 --> 00:28:23,082 But amongst this wreck, there's no cargo to be found. 360 00:28:23,285 --> 00:28:25,018 -What does that mean? 361 00:28:25,120 --> 00:28:27,821 Well it means the ship was either sailing in ballast, that is empty, 362 00:28:27,923 --> 00:28:31,558 or it had a cargo that was perishable, and that perishable cargo could have 363 00:28:31,560 --> 00:28:37,964 been everything from rice or grain, to one possibility being a very sobering thought 364 00:28:38,033 --> 00:28:40,634 and that is it could have been carrying people. 365 00:28:40,735 --> 00:28:44,037 It may have been a vessel engaged in the illegal slave trade. 366 00:28:45,006 --> 00:28:49,375 NARRATOR: The trans-Atlantic slave trade sees slaves violently captured and 367 00:28:49,378 --> 00:28:53,113 shipped from West Africa, and then forced to work on US plantations. 368 00:28:55,050 --> 00:29:00,253 Although owning slaves remains lawful, the import of new ones is outlawed by 369 00:29:00,322 --> 00:29:02,856 Congress in 1807. 370 00:29:03,659 --> 00:29:08,729 Great Britain also bans the trade and uses its navy to hunt down and 371 00:29:08,731 --> 00:29:11,331 capture slave ships. 372 00:29:11,600 --> 00:29:14,000 With much money still to be made, 373 00:29:14,069 --> 00:29:17,471 smugglers continue to bring captured African men, 374 00:29:17,540 --> 00:29:23,076 women and children through the Gulf of Mexico and into its maze of channels and 375 00:29:23,178 --> 00:29:26,880 waterways, aiming for New Orleans and its slave markets. 376 00:29:27,216 --> 00:29:31,418 Is wreck C involved in this brutal, callous business? 377 00:29:31,720 --> 00:29:35,689 -Now we didn't see manacles or anything of that sort but in this period, when it's lost, 378 00:29:35,791 --> 00:29:39,493 it's entirely possible, as we know from other cases, that people were simply locked 379 00:29:39,562 --> 00:29:43,696 below in the hold, and with those that were most capable of trying to escape 380 00:29:43,732 --> 00:29:46,366 being tied up. 381 00:29:47,603 --> 00:29:50,704 NARRATOR: The team begin to piece together the evidence. 382 00:29:50,706 --> 00:29:54,574 -In thinking about these ships as a convoy, we can hypothesize a 383 00:29:54,676 --> 00:29:56,777 variety of scenarios. 384 00:29:56,879 --> 00:30:01,047 The first would be it's an armed escort with two merchant ships that need protection to 385 00:30:01,050 --> 00:30:03,684 get from one port to another. 386 00:30:03,686 --> 00:30:07,987 It could be a privateer with two prizes that it captured. 387 00:30:08,057 --> 00:30:13,393 In looking at the cargo on the second ship we have stacks and stacks of cow hides. 388 00:30:14,696 --> 00:30:18,098 Those would have brought a great price at the market, even if you were smuggling. 389 00:30:20,002 --> 00:30:24,304 NARRATOR: To unravel the mystery further, they select a range of artifacts and bring 390 00:30:24,406 --> 00:30:27,040 them to the surface. 391 00:30:31,814 --> 00:30:35,015 They could reveal once and for all who was on board. 392 00:30:35,717 --> 00:30:38,985 AMY: One of the unique things about this particular shipwreck Monterrey shipwreck-A 393 00:30:39,054 --> 00:30:42,756 was the cannons and the presence of muskets. 394 00:30:43,025 --> 00:30:45,725 Those were all British types, British military musket types. 395 00:30:45,728 --> 00:30:48,428 They were absolutely ubiquitous in this region during the first half of the 396 00:30:48,530 --> 00:30:52,265 19th century, so having British muskets on a ship does not mean that it's 397 00:30:52,301 --> 00:30:54,101 a British vessel. 398 00:30:54,203 --> 00:30:57,103 NARRATOR: The crews' nationality remains a mystery. 399 00:30:57,205 --> 00:31:01,241 But there are other clues that may tell us what caused the ships to sink. 400 00:31:01,710 --> 00:31:05,445 AMY: A portion of the collection that was recovered were navigational tools. 401 00:31:05,447 --> 00:31:09,449 The importance of these tools was so great that you would have wanted to have taken 402 00:31:09,551 --> 00:31:13,920 those with you so leaving them on the ship is foreboding and you know, 403 00:31:14,022 --> 00:31:16,489 it suggests that maybe everyone perished. 404 00:31:18,060 --> 00:31:22,429 NARRATOR: The Gulf of Mexico is notorious for a particularly violent force of 405 00:31:22,431 --> 00:31:26,566 nature: hurricanes, giving rise to one likely scenario. 406 00:31:28,303 --> 00:31:31,270 JAMES: All three of them were running together in what clearly was a 407 00:31:31,307 --> 00:31:33,840 very violent storm. 408 00:31:33,942 --> 00:31:37,277 You had a quick moment to look on the horizon, see the other guys there and 409 00:31:37,379 --> 00:31:40,413 then their lights disappear if it's at night or they disappear in a squall. 410 00:31:40,915 --> 00:31:45,151 And the next thing you know the Gulf is coming over your own decks and you're being 411 00:31:45,187 --> 00:31:47,921 dragged down into the depths, and into the darkness. 412 00:31:48,924 --> 00:31:52,759 NARRATOR: The Monterrey group of wrecks provides a new insight into the maritime 413 00:31:52,861 --> 00:31:55,228 history of the Gulf of Mexico, 414 00:31:55,297 --> 00:31:58,098 at a turning point in US history. 415 00:31:58,200 --> 00:32:01,501 FREDRICK: The Monterey shipwrecks are important because they're evidence of that 416 00:32:01,503 --> 00:32:02,936 transition to the birth of a new nation. 417 00:32:02,938 --> 00:32:05,806 How trade continued while the Spanish empire crumbled. 418 00:32:05,907 --> 00:32:09,242 Why New Orleans was such an important part of this interregional, 419 00:32:09,244 --> 00:32:11,378 burgeoning global trade. 420 00:32:11,480 --> 00:32:15,282 And that's what those shipwrecks speak to and that's what they're symbolic of. 421 00:32:17,352 --> 00:32:20,587 NARRATOR: The Monterrey wrecks are not alone. 422 00:32:20,756 --> 00:32:24,457 As the water drains away further, leaving the darkest depths of the 423 00:32:24,559 --> 00:32:26,727 Gulf of Mexico exposed, 424 00:32:26,729 --> 00:32:30,997 one of the most extraordinary stories of all is about to be revealed: 425 00:32:31,667 --> 00:32:36,536 a state-of-the-art WW2 submarine, not American but German. 426 00:32:37,405 --> 00:32:42,275 What was Nazi submarine U-166 doing in the Gulf of Mexico? 427 00:32:42,678 --> 00:32:45,445 And how did it meet its end? 428 00:32:49,034 --> 00:32:54,371 ♪ ♪ 429 00:32:55,374 --> 00:32:57,974 NARRATOR: December 11, 1941. 430 00:32:58,711 --> 00:33:01,778 Hitler declares war on the United States. 431 00:33:17,829 --> 00:33:21,731 NARRATOR: When the US enters the war, a new battleground opens up... 432 00:33:22,267 --> 00:33:24,534 The Gulf of Mexico. 433 00:33:24,937 --> 00:33:29,940 Today, by draining away its dark waters, it's possible to reveal secrets from this 434 00:33:30,409 --> 00:33:36,146 desperate period of conflict, when a ruthless battle to rule the waves comes to America's 435 00:33:36,148 --> 00:33:42,753 own shores and solve a mystery which has baffled historians for over 70 years. 436 00:33:48,060 --> 00:33:52,629 Immediately after entering World War II, the US faces a deadly peril, 437 00:33:52,698 --> 00:33:55,598 off its eastern seaboard. 438 00:33:55,667 --> 00:33:58,335 Nazi U-boats. 439 00:34:00,338 --> 00:34:05,642 Their objective is to disrupt Allied shipping bound for Europe, at the source. 440 00:34:06,445 --> 00:34:10,614 The U-boat commanders are highly experienced, having honed their skills 441 00:34:10,716 --> 00:34:12,982 in battle since 1939. 442 00:34:13,618 --> 00:34:17,487 The United States is completely unprepared for them. 443 00:34:17,823 --> 00:34:22,192 ERIC: Ships were escorted across the North Atlantic in convoys both ways. 444 00:34:22,293 --> 00:34:23,727 But once they got into American coastal waters they were unescorted, 445 00:34:23,729 --> 00:34:28,865 and they were therefore easy targets for the U-boats. 446 00:34:28,867 --> 00:34:33,069 NARRATOR: To make matters worse, the US government fails to impose a blackout. 447 00:34:33,171 --> 00:34:37,140 Ships sailing along the coast at night are perfectly silhouetted. 448 00:34:37,142 --> 00:34:38,675 Sitting ducks. 449 00:34:39,077 --> 00:34:41,011 -And this was a key vulnerability the Germans noticed, 450 00:34:41,013 --> 00:34:44,180 and they sent their submarines in to exploit it. 451 00:34:45,751 --> 00:34:50,353 NARRATOR: German submarine commanders call it 'American shooting season'. 452 00:34:52,524 --> 00:34:57,760 Between January and June 1942, more tonnage is sunk off the U.S. 453 00:34:57,796 --> 00:35:03,032 coast than the Allies have lost during the previous two and a half years, 454 00:35:03,134 --> 00:35:06,703 as the Nazis try to starve Britain of vital supplies. 455 00:35:07,773 --> 00:35:11,074 The U Boats then take the war into the Gulf of Mexico. 456 00:35:14,713 --> 00:35:17,614 And the reason is oil. 457 00:35:18,016 --> 00:35:21,384 -Most of the world's oil at this time came through the Gulf of Mexico, 458 00:35:21,486 --> 00:35:25,522 hence it was the equivalent to the Arabian Gulf today. 459 00:35:27,326 --> 00:35:29,592 NARRATOR: It's not just oil tankers. 460 00:35:29,595 --> 00:35:32,929 Any Allied ship is seen as fair game. 461 00:35:32,931 --> 00:35:35,965 JAMES: A U-boat skipper did not want to pass up on the opportunity to sink what might 462 00:35:36,001 --> 00:35:39,869 be a valuable cargo of a specific commodity, be it foodstuffs, 463 00:35:39,871 --> 00:35:41,905 be it machinery or parts. 464 00:35:42,007 --> 00:35:45,575 He couldn't know for certain, but he did know that if he sent a ship to the bottom he 465 00:35:45,644 --> 00:35:47,677 was aiding the German war effort. 466 00:35:48,213 --> 00:35:51,347 NARRATOR: One such ship is the Robert E Lee. 467 00:35:51,717 --> 00:35:53,917 ROB: The Robert E. Lee was a passenger freighter. 468 00:35:54,018 --> 00:35:59,155 It was coming from Trinidad up to New Orleans and it actually was carrying American 469 00:35:59,257 --> 00:36:04,661 construction workers and also a lot of other passengers that were victims 470 00:36:04,663 --> 00:36:06,563 on previous U-Boat sinking's. 471 00:36:08,934 --> 00:36:12,101 NARRATOR: As the Robert E Lee approaches New Orleans, 472 00:36:12,137 --> 00:36:15,004 U-166 is on patrol. 473 00:36:15,040 --> 00:36:21,511 One of the latest German long-range submarines, U-166 is capable of traveling across 474 00:36:21,580 --> 00:36:25,181 the Atlantic without the need to refuel. 475 00:36:25,417 --> 00:36:32,055 A thoroughbred ocean predator, commanded by battle-hardened Captain Hans Gunther Kuhlmann. 476 00:36:32,156 --> 00:36:35,391 ROB: Hans Gunther Kuhlmann had not had a lot of success during this mission. 477 00:36:35,460 --> 00:36:40,063 He had sank a couple of small boat, including one that was just a few tons. 478 00:36:40,132 --> 00:36:43,332 It actually bore the same name of his wife, Gertrude. 479 00:36:43,402 --> 00:36:49,338 And so as soon as he saw a large vessel over 5,000 tons, it was a big target and it was 480 00:36:49,374 --> 00:36:52,409 an opportunity for him to get some tonnage under his belt. 481 00:36:54,079 --> 00:36:58,047 NARRATOR: The details of the battle, including the fate of U-166, 482 00:36:58,083 --> 00:37:02,652 for years remain one of the Gulf of Mexico's greatest mysteries. 483 00:37:03,154 --> 00:37:08,291 Rob Church is a marine archaeologist for a company performing surveys of the 484 00:37:08,393 --> 00:37:10,960 sea floor for the oil and gas industry. 485 00:37:10,963 --> 00:37:15,965 When a wreck is discovered, his job is to assess its historical importance. 486 00:37:16,067 --> 00:37:18,968 -So, this is a typical inspection class ROV. 487 00:37:19,070 --> 00:37:20,704 It is a 3,000-meter rated system. 488 00:37:20,805 --> 00:37:22,772 On this particular one right now we have three camera arrays here. 489 00:37:22,808 --> 00:37:25,842 We have the two stereo cameras for collecting 3D video. 490 00:37:25,844 --> 00:37:30,480 We have the HD camera above them for collecting high resolution video. 491 00:37:30,581 --> 00:37:34,451 We also have a seven-function manipulator arm which allows us to be able to pick up 492 00:37:34,453 --> 00:37:39,656 things on the sea floor; collect samples, also ah set out experiments, etcetera. 493 00:37:39,757 --> 00:37:42,258 And then we have a scanning sonar. 494 00:37:42,327 --> 00:37:46,996 This allows us to detect targets on the sea floor to inspect or we can also use it 495 00:37:46,999 --> 00:37:48,565 navigate around shipwrecks. 496 00:37:50,602 --> 00:37:54,738 NARRATOR: While conducting an oil pipeline survey using an ROV similar to this, 497 00:37:54,839 --> 00:37:57,741 Rob Church comes across a wreck. 498 00:37:58,610 --> 00:38:01,077 ROB: We approached from the stern and you could see the railing, 499 00:38:01,079 --> 00:38:03,079 you could see the decks of that passenger freighter 500 00:38:03,181 --> 00:38:05,782 and there was no doubt at that point that we were looking at the Robert E. Lee. 501 00:38:07,352 --> 00:38:08,752 This was a thrilling moment. 502 00:38:08,853 --> 00:38:12,288 And to see a boat like the Robert E. Lee, 503 00:38:12,290 --> 00:38:15,759 which is really a beautiful wreck site, it was incredible. 504 00:38:20,098 --> 00:38:26,603 NARRATOR: Over 5,000 feet down, the ROV scans the site collecting valuable data. 505 00:38:29,741 --> 00:38:34,977 From this, it's possible to drain away the ocean and see the drowned vessel as she is 506 00:38:35,079 --> 00:38:40,183 today but this time, exposed to the sunlight. 507 00:38:42,453 --> 00:38:47,790 As the water pours away, the wreck of the Robert E Lee is revealed in extraordinary 508 00:38:47,826 --> 00:38:52,228 detail, providing new evidence on her final moments. 509 00:38:54,031 --> 00:38:59,736 The bridge is gone, unable to withstand the forces of drag as the ship plummeted 510 00:38:59,838 --> 00:39:01,404 through the water. 511 00:39:03,308 --> 00:39:08,511 The deck gun on the stern is in the stored position showing the attack 512 00:39:08,580 --> 00:39:10,914 is sudden and unexpected. 513 00:39:12,250 --> 00:39:15,952 And lying next to the wreck are two lifeboats. 514 00:39:16,354 --> 00:39:22,024 The speed with which the ship goes down does not give the crew time to deploy them. 515 00:39:22,327 --> 00:39:27,464 Experts calculate that it takes just three minutes for the Robert E Lee to sink. 516 00:39:28,032 --> 00:39:32,168 But one important part of the puzzle remains unanswered. 517 00:39:32,270 --> 00:39:37,373 What happened to the U-boat that fired the deadly torpedo? 518 00:39:37,375 --> 00:39:41,911 As the water continues to drain away from the wreck of the Robert E Lee, 519 00:39:42,113 --> 00:39:46,549 one of the Gulf of Mexico's biggest maritime mysteries is about to be solved. 520 00:39:55,543 --> 00:39:58,378 NARRATOR: July 30, 1942. 521 00:40:00,015 --> 00:40:05,652 The German submarine U-166 fires a fatal shot at the merchant vessel, 522 00:40:05,753 --> 00:40:09,489 Robert E. Lee off the coast of New Orleans. 523 00:40:10,992 --> 00:40:14,027 It sinks in three minutes. 524 00:40:14,129 --> 00:40:17,030 But the Robert E Lee is not alone. 525 00:40:17,365 --> 00:40:24,637 It's escorted by a submarine chaser Patrol Craft 566, captained by Herbert Claudius. 526 00:40:24,906 --> 00:40:28,775 ROB: The indications are that the U-Boat had no idea that the patrol craft was 527 00:40:28,910 --> 00:40:30,843 bearing down on them. 528 00:40:30,945 --> 00:40:32,378 They were proceeding at periscope depth watching the 529 00:40:32,447 --> 00:40:34,514 Robert E. Lee sink. 530 00:40:34,516 --> 00:40:38,351 It wasn't until the patrol craft got within range and began actively pinging sonar 531 00:40:38,386 --> 00:40:41,854 against the hull that they first apparently realized they were under attack at that 532 00:40:41,923 --> 00:40:46,192 moment and began to dive. 533 00:40:46,394 --> 00:40:50,363 JAMES: Within very short range, the hunter becomes the hunted. 534 00:40:50,599 --> 00:40:54,266 NARRATOR: As Patrol Craft 566 passes over the U-boat, 535 00:40:54,302 --> 00:40:58,505 Captain Claudius fires two rounds of depth charges. 536 00:41:01,343 --> 00:41:05,945 Unable to confirm a kill, he turns his attention to rescuing survivors 537 00:41:06,014 --> 00:41:07,580 of the Robert E Lee. 538 00:41:07,915 --> 00:41:12,085 The fate of U-166 remains unknown. 539 00:41:12,687 --> 00:41:19,892 Two days later a US Coast Guard plane spots a U-boat surfacing 140 miles away. 540 00:41:19,994 --> 00:41:26,466 It drops a single depth charge and the U-boat disappears. 541 00:41:28,169 --> 00:41:32,238 The plane crew is credited with sinking U-166. 542 00:41:32,707 --> 00:41:36,109 But despite extensive scanning of the sea floor, 543 00:41:36,111 --> 00:41:39,312 no trace of a wreck is ever found. 544 00:41:39,580 --> 00:41:45,451 -Finding something that so many people had looked for so long it's kind of you know, 545 00:41:45,553 --> 00:41:47,754 it takes an element of luck. 546 00:41:48,256 --> 00:41:52,125 NARRATOR: Studying a sonar scan of the sea bed around the Robert E Lee, 547 00:41:52,327 --> 00:41:57,196 Church spots a mysterious object, less than two miles away from the wreck. 548 00:41:57,198 --> 00:42:00,866 ROB: So, as I first saw the image I realized it had potential. 549 00:42:00,869 --> 00:42:06,905 But it was about 50, 60 feet short of the dimensions of a Type 9C German U Boat. 550 00:42:06,908 --> 00:42:12,812 NARRATOR: What was this mysterious wreck, 140 miles away from where U-166 was 551 00:42:12,881 --> 00:42:15,348 believed to have sunk? 552 00:42:15,350 --> 00:42:17,850 Could it be the missing sub? 553 00:42:17,985 --> 00:42:21,487 Further draining of the ocean uncovers the truth. 554 00:42:21,823 --> 00:42:26,926 As the water recedes, light begins to pour onto this mystery vessel. 555 00:42:27,128 --> 00:42:33,166 The conning tower of a German U-boat gradually appears, its antenna unretracted 556 00:42:33,267 --> 00:42:37,637 indicating it dived suddenly and under duress. 557 00:42:37,806 --> 00:42:43,843 Next, its hull is exposed to the sky for the first time in over 70 years. 558 00:42:44,145 --> 00:42:48,781 The configuration of the conning tower and deck guns exactly matches 559 00:42:48,916 --> 00:42:51,584 the missing U-166. 560 00:42:51,686 --> 00:42:57,323 And from another angle, the reason the sonar image is short suddenly becomes clear. 561 00:42:57,425 --> 00:43:02,594 The U-boat's bow is missing, blown off by a massive explosion. 562 00:43:02,897 --> 00:43:07,333 As the water continues to drain away, the missing section is revealed, 563 00:43:07,435 --> 00:43:10,870 lying 500 feet away. 564 00:43:10,971 --> 00:43:16,609 A depth charge alone could not have caused such catastrophic damage. 565 00:43:17,545 --> 00:43:20,146 So, what happened? 566 00:43:20,248 --> 00:43:24,550 -It appears that after one of the depth charges breached the pressure hull that it probably 567 00:43:24,652 --> 00:43:31,658 set off an internal explosion which then ripped the bow section off. 568 00:43:31,759 --> 00:43:34,894 ERIC: When the submarine dived, perhaps torpedoes became loose and it was more 569 00:43:34,995 --> 00:43:36,962 likely that an explosion would occur. 570 00:43:36,965 --> 00:43:40,099 This was a successful depth charge attack and it was clear that this was actually 571 00:43:40,168 --> 00:43:44,637 sunk as claimed by the submarine chaser. 572 00:43:44,639 --> 00:43:52,578 NARRATOR: 22 people lost their lives on the Robert E Lee and all 52 perished on the U-166. 573 00:43:52,580 --> 00:43:57,750 The two wrecks are now considered a war grave and cannot be salvaged. 574 00:43:58,019 --> 00:44:02,054 Draining the ocean is the only way to bring the wrecks to the surface and 575 00:44:02,090 --> 00:44:05,858 in the process set the record straight. 576 00:44:06,127 --> 00:44:09,595 With the U-boat discovered lying less than two miles from the Robert E Lee, 577 00:44:09,597 --> 00:44:12,865 there can be no doubt who sank it. 578 00:44:12,867 --> 00:44:18,905 The kill is now credited to Herbert Claudius, captain of Patrol Craft 566. 579 00:44:19,540 --> 00:44:25,945 Soon after the sinking of U-166, the tide begins to turn in the Battle of the Atlantic. 580 00:44:26,514 --> 00:44:31,717 -Inevitably, the Allies were able to push back against the U-boat assault thanks 581 00:44:31,786 --> 00:44:33,953 to a variety of factors. 582 00:44:33,988 --> 00:44:39,024 Increased surveillance, more convoys, as well as the ability to strike from the air, 583 00:44:39,126 --> 00:44:41,794 the U-boats were steadily defeated. 584 00:44:45,400 --> 00:44:50,570 NARRATOR: Nevertheless, during the Second World War, while operating in US waters, 585 00:44:50,638 --> 00:44:58,110 the German navy sends 609 Allied ships to the bottom of the ocean with the loss of 586 00:44:58,179 --> 00:45:01,114 only 12 U-boats. 587 00:45:02,450 --> 00:45:07,887 Of those, only one submarine is sunk in the Gulf of Mexico... 588 00:45:07,889 --> 00:45:10,423 U-166. 589 00:45:12,727 --> 00:45:18,531 Looking below the waters of the Gulf of Mexico has solved long lost mysteries and 590 00:45:18,566 --> 00:45:25,404 brought deadly secrets back to the surface showing that the story of North America: 591 00:45:25,473 --> 00:45:31,477 through trade, war and even the death of the dinosaurs can only be fully 592 00:45:31,612 --> 00:45:36,449 seen and understood by draining the oceans. 593 00:45:37,752 --> 00:45:39,152 Captioned by Cotter Captioning Services.