1 00:00:10,133 --> 00:00:14,467 NARRATOR: Deep beneath the tropical waters of the Gulf of Mexico lies a 2 00:00:14,500 --> 00:00:19,267 seething history of piracy, slavery and bitter conflict. 3 00:00:20,700 --> 00:00:23,533 FRITZ: The Gulf of Mexico was the wild west of the sea and it's every man for himself. 4 00:00:25,333 --> 00:00:31,000 NARRATOR: Imagine if we could empty the oceans, letting the water drain away to reveal 5 00:00:31,033 --> 00:00:33,333 the secrets of the sea floor? 6 00:00:36,567 --> 00:00:39,067 Now we can. 7 00:00:41,400 --> 00:00:46,500 Using the latest underwater scanning technology, piercing the deep oceans and turning 8 00:00:47,233 --> 00:00:51,000 accurate data into 3D images. 9 00:00:53,233 --> 00:00:58,933 This time, why did a deadly German U-Boat end up at the bottom of the ocean off 10 00:00:59,433 --> 00:01:01,533 the coast of New Orleans? 11 00:01:01,567 --> 00:01:04,267 JAMES: Within very short range, the hunter becomes the hunted. 12 00:01:05,700 --> 00:01:10,167 NARRATOR: Who was on board this mysterious wreck, from a time when pirates and 13 00:01:10,200 --> 00:01:13,033 slave traders ruled the waves? 14 00:01:13,700 --> 00:01:17,833 How did a single asteroid impact in the Gulf of Mexico 15 00:01:17,867 --> 00:01:20,933 wipe out the dinosaurs around the globe? 16 00:01:21,833 --> 00:01:25,033 KEN: The base of the food chain is knocked out and things begin to starve. 17 00:01:26,233 --> 00:01:30,600 NARRATOR: And how did drilling for oil result in one of the biggest environmental 18 00:01:30,633 --> 00:01:32,833 disasters in US history? 19 00:01:34,033 --> 00:01:36,833 DAVE: In theory, that well should have been easy. 20 00:01:39,267 --> 00:01:44,733 NARRATOR: Draining the oceans shines new light on the secrets of the Gulf of Mexico. 21 00:01:59,333 --> 00:02:03,833 66 million years ago, dinosaurs roam the Earth. 22 00:02:04,767 --> 00:02:09,867 Then, in a geological instant, they are wiped out, around the planet. 23 00:02:11,667 --> 00:02:15,400 Can draining the water from the Gulf of Mexico explain why? 24 00:02:21,500 --> 00:02:26,900 The story begins not in the Gulf but over 1,500 miles away in New Jersey. 25 00:02:29,367 --> 00:02:34,300 This former quarry is one of the most important fossil sites in the world, 26 00:02:34,333 --> 00:02:39,133 because here, paleontologists discover a mass prehistoric graveyard. 27 00:02:40,533 --> 00:02:45,600 -This is the boundary between the cretaceous period, the age of the dinosaurs and 28 00:02:45,633 --> 00:02:48,000 the age that comes after that, the Paleogene. 29 00:02:48,033 --> 00:02:53,200 And what we have here is a bone bed, where we have about 25 fossils per square meter. 30 00:02:54,100 --> 00:02:59,767 Paleontologists have never found an in-place dinosaur bone one centimeter above that 31 00:03:00,667 --> 00:03:03,400 extinction layer anywhere on the planet. 32 00:03:03,800 --> 00:03:08,067 NARRATOR: The absence of dinosaur fossils above this layer can mean only one thing. 33 00:03:08,733 --> 00:03:11,000 They were wiped out by a sudden, 34 00:03:11,033 --> 00:03:13,967 cataclysmic event, 66 million years ago. 35 00:03:14,733 --> 00:03:19,533 -Whatever took out the dinosaurs was global, terrible and instantaneous. 36 00:03:20,833 --> 00:03:23,433 NARRATOR: Experts have offered many answers. 37 00:03:23,467 --> 00:03:26,100 But only one is widely accepted. 38 00:03:26,400 --> 00:03:30,900 -By far the leading explanation is that an asteroid hit the earth 39 00:03:30,933 --> 00:03:35,200 66 million years ago and unleashed hell on earth and took out the dinosaurs 40 00:03:35,233 --> 00:03:38,367 and 75% of life. 41 00:03:38,700 --> 00:03:41,033 NARRATOR: Scientists scour the planet. 42 00:03:41,067 --> 00:03:43,933 Looking for evidence of asteroid strikes. 43 00:03:48,933 --> 00:03:53,567 But none of the impact craters that they find are big enough and of the right 44 00:03:53,600 --> 00:03:56,567 age to be the culprit. 45 00:03:57,133 --> 00:04:01,800 Then, in Mexico's Yucatan peninsula, they find a surprising lead. 46 00:04:05,967 --> 00:04:10,833 Mario Rebolledo, is an expert in a remarkable natural phenomenon found all 47 00:04:10,867 --> 00:04:12,967 over this region. 48 00:04:13,000 --> 00:04:16,867 Sinkholes, known locally as cenotes, 49 00:04:20,067 --> 00:04:22,667 formed by the erosion of soft limestone, 50 00:04:22,700 --> 00:04:25,800 they can be hundreds of feet deep. 51 00:04:27,167 --> 00:04:29,800 Exploring them requires years of experience. 52 00:04:51,633 --> 00:04:55,233 NARRATOR: Mario discovers that many of the cenotes are linked through deep, 53 00:04:55,267 --> 00:04:57,867 subterranean channels. 54 00:05:00,367 --> 00:05:02,267 But that's not all. 55 00:05:02,300 --> 00:05:04,800 They also display a remarkably similar structure. 56 00:05:30,667 --> 00:05:34,800 NARRATOR: When seen from above, an extraordinary picture begins to emerge. 57 00:05:35,900 --> 00:05:38,833 The cenotes form an outline. 58 00:05:40,300 --> 00:05:44,100 It looks like the rim of a gigantic crater. 59 00:05:44,367 --> 00:05:49,733 The most likely explanation is that a massive asteroid strike reshaped this region and then 60 00:05:50,333 --> 00:05:54,100 the sinkholes formed in fault lines around its edge. 61 00:05:54,633 --> 00:05:58,867 Could this be the crater that's linked to the death of the dinosaurs? 62 00:05:59,400 --> 00:06:05,800 Today, millions of years after it was created, the heart of the impact site lies concealed 63 00:06:05,833 --> 00:06:10,867 not just under the waters of the Gulf of Mexico, but under several thousand feet of 64 00:06:10,900 --> 00:06:13,533 sedimentary rock. 65 00:06:13,833 --> 00:06:19,333 The only way to calculate its age and see if it dates from the demise of the dinosaurs is 66 00:06:19,367 --> 00:06:22,633 to analyze rocks from the crater itself. 67 00:06:24,567 --> 00:06:28,900 SEAN: To really understand impact cratering we actually need to pull rocks 68 00:06:28,933 --> 00:06:31,133 from ground zero. 69 00:06:31,167 --> 00:06:35,033 We need to find a place where we know that the damage has been the greatest in 70 00:06:35,967 --> 00:06:39,067 order to get a sense of the way impact craters work. 71 00:06:41,967 --> 00:06:46,767 NARRATOR: In 2016, an international team of scientists drill down from 72 00:06:46,800 --> 00:06:49,567 this specially adapted oil platform. 73 00:06:50,500 --> 00:06:53,967 SEAN: And so, we were pulling up limestone after limestone after limestone. 74 00:06:54,000 --> 00:06:56,567 We're getting ages from the fossils within them. 75 00:06:56,600 --> 00:07:00,667 We know we are at 48 or 50 million years but we're not yet at 66, right. 76 00:07:01,267 --> 00:07:04,367 And then things suddenly jumped in time. 77 00:07:04,400 --> 00:07:08,500 NARRATOR: The team hits a layer of melted rock, indicating an asteroid strike. 78 00:07:09,467 --> 00:07:13,733 And samples confirm that the rocks are 66 million years old, 79 00:07:14,233 --> 00:07:17,167 the exact moment when the dinosaurs died. 80 00:07:19,433 --> 00:07:24,067 Next, the team analyze the rocks to calculate the asteroid's power 81 00:07:27,200 --> 00:07:31,733 comparing their data to that generated by nuclear bomb tests. 82 00:07:34,067 --> 00:07:38,267 -And we can come up with an estimate of the amount of energy released and that turns 83 00:07:38,300 --> 00:07:40,933 out to be about ten billion Hiroshima's. 84 00:07:47,733 --> 00:07:51,600 NARRATOR: Using this data, it's possible, for the very first time, 85 00:07:51,633 --> 00:07:58,167 to create a 3D visualization of the crater, now hidden deep beneath the Earth and discover 86 00:07:59,033 --> 00:08:03,400 how a single asteroid impact in the Gulf of Mexico could wipe out 87 00:08:03,433 --> 00:08:06,233 dinosaurs around the globe. 88 00:08:07,500 --> 00:08:11,433 First, the entire Gulf must be drained away. 89 00:08:11,467 --> 00:08:15,833 As the water recedes, it reveals a vast continental shelf running 90 00:08:15,867 --> 00:08:18,333 around the coastline. 91 00:08:18,367 --> 00:08:23,367 The crumpled plain is thick with sediment, but the crater is still hidden under 92 00:08:23,400 --> 00:08:25,800 thousands of feet of rock. 93 00:08:27,267 --> 00:08:33,700 66 million years of geology must now be rolled back, draining away layer upon layer 94 00:08:34,633 --> 00:08:40,967 of sedimentary rock, until the impact site begins to emerge, a sight that no living 95 00:08:41,000 --> 00:08:45,100 creature has witnessed for 66 million years. 96 00:08:45,800 --> 00:08:48,833 The crater is immense. 97 00:08:48,867 --> 00:08:53,100 Over half a mile deep and 120 miles wide. 98 00:08:53,500 --> 00:08:58,100 Around its edge towers the outer rim, formed by rock ejected from deep 99 00:08:58,133 --> 00:09:00,900 within the Earth's crust. 100 00:09:00,933 --> 00:09:05,700 Now, by studying the crater's profile, it's possible to determine the size and speed 101 00:09:05,733 --> 00:09:08,033 of the asteroid. 102 00:09:08,067 --> 00:09:12,700 It's over 7 miles wide and it travels at 40,000 miles per hour. 103 00:09:14,700 --> 00:09:18,000 And the crater's dimensions tell us something else. 104 00:09:18,033 --> 00:09:22,100 30,000 cubic miles of rock are displaced here. 105 00:09:22,133 --> 00:09:27,200 Vast amounts hurled into the atmosphere, setting off a devastating chain of events. 106 00:09:30,500 --> 00:09:34,933 -It blows a hole in the ground about the size of the State of Massachusetts. 107 00:09:35,467 --> 00:09:39,233 Now all that rock, it gets pulverized, thrown up through the earth's atmosphere. 108 00:09:39,833 --> 00:09:43,233 It starts to orbit the planet and when that rock comes back in, 109 00:09:43,667 --> 00:09:46,867 it's got a tremendous amount potential gravitational energy. 110 00:09:46,900 --> 00:09:50,800 it heats up the atmosphere to toaster oven or pizza oven temperatures, 111 00:09:50,833 --> 00:09:53,967 frying everything that doesn't have a place to hide. 112 00:09:54,900 --> 00:09:58,933 NARRATOR: Almost every living creature within 600 miles is killed by 113 00:09:58,967 --> 00:10:00,967 this deadly fireball. 114 00:10:01,000 --> 00:10:04,167 But those further away do not escape. 115 00:10:04,500 --> 00:10:08,000 -Later that day the tsunami waves wash up on the shore. 116 00:10:08,033 --> 00:10:11,967 These could have been hundreds of feet tall, maybe even half a mile tall when they hit 117 00:10:12,000 --> 00:10:15,033 here, and they would have run up through the continent. 118 00:10:15,067 --> 00:10:18,133 Animals that are still alive would have heard the wave coming for them 119 00:10:18,167 --> 00:10:21,033 but wouldn't have seen it in the darkness. 120 00:10:21,067 --> 00:10:24,333 NARRATOR: But the asteroid strike becomes a truly global disaster for 121 00:10:24,367 --> 00:10:26,867 one specific reason... 122 00:10:26,900 --> 00:10:29,500 where it hits Earth. 123 00:10:30,167 --> 00:10:33,800 This part of the planet contains rocks high in Sulphur. 124 00:10:33,833 --> 00:10:38,167 On impact, the Sulphur is vaporized and blasted high above the Earth. 125 00:10:39,000 --> 00:10:42,567 -Well that Sulphur combines with the atmosphere and becomes sulphate aerosols and 126 00:10:42,600 --> 00:10:46,267 sulphate aerosols are excellent at blocking sunlight. 127 00:10:46,567 --> 00:10:51,300 NARRATOR: This deadly cloud shrouds the planet and the Earth begins to cool. 128 00:10:53,533 --> 00:10:58,533 By studying the crater in more detail it's possible to see new evidence of how the 129 00:10:58,567 --> 00:11:02,233 crater's shape makes the Sulphur cloud even more deadly. 130 00:11:03,567 --> 00:11:06,133 The north-east rim is open. 131 00:11:06,167 --> 00:11:10,733 The asteroid hits deep water here absorbing some of the impact and 132 00:11:10,767 --> 00:11:14,367 thirty minutes later the ocean rushes back in. 133 00:11:15,833 --> 00:11:19,767 Water vapor from this tsunami combines with the Sulphur to form 134 00:11:19,800 --> 00:11:23,333 sunlight- blocking gases in even larger quantities. 135 00:11:24,967 --> 00:11:28,833 -The plankton in the ocean can't do photosynthesis and pretty soon the base of the 136 00:11:28,867 --> 00:11:31,867 food chain is knocked out and things begin to starve. 137 00:11:34,467 --> 00:11:38,800 NARRATOR: Lack of sunlight means the entire planet experiences an average cooling 138 00:11:38,833 --> 00:11:42,433 of 47 degrees Fahrenheit for up to 16 years. 139 00:11:44,533 --> 00:11:48,367 Only the toughest plants and animals survive. 140 00:11:48,400 --> 00:11:51,167 The dinosaurs do not. 141 00:11:52,100 --> 00:11:57,267 One question remains, was this event unique or could it happen again, 142 00:11:57,733 --> 00:12:00,733 this time wiping out human-kind? 143 00:12:01,533 --> 00:12:05,767 -There are other near-Earth objects out there, asteroids just like the one that took 144 00:12:05,800 --> 00:12:09,433 out the dinosaurs and we do not know where they all are. 145 00:12:09,467 --> 00:12:13,467 Every day, scientists are discovering more and more asteroids that have the power 146 00:12:13,500 --> 00:12:15,900 to menace our earth. 147 00:12:18,700 --> 00:12:21,233 SEAN: Now, we think we've tracked all the big ones. 148 00:12:21,267 --> 00:12:24,500 So, we don't think there is another event that is just around the corner, 149 00:12:24,533 --> 00:12:29,800 but that doesn't mean we shouldn't keep making sure, given the circumstances. 150 00:12:30,900 --> 00:12:35,700 NARRATOR: As we drain the Gulf of Mexico further, it's possible to reveal areas 151 00:12:35,733 --> 00:12:39,400 where humans are drilling thousands of feet below the sea bed 152 00:12:39,433 --> 00:12:44,200 to exploit a natural resource formed 100 million years ago... 153 00:12:45,633 --> 00:12:48,167 oil. 154 00:12:48,200 --> 00:12:52,633 But how did a failure while drilling in the Gulf of Mexico turn into the biggest oil 155 00:12:52,667 --> 00:12:55,067 spill in US history? 156 00:13:01,133 --> 00:13:04,367 NARRATOR: The economy of the Gulf of Mexico is driven by oil. 157 00:13:06,133 --> 00:13:12,233 This vast, oil rich basin accounts for 17% of total US crude oil production. 158 00:13:13,700 --> 00:13:18,667 Nearly half of America's oil refining capacity sits along the Gulf coast. 159 00:13:19,833 --> 00:13:24,267 But it's offshore that the scale of the infrastructure needed to bring oil to the 160 00:13:24,300 --> 00:13:27,467 surface is truly staggering. 161 00:13:30,133 --> 00:13:35,100 Using the latest data and visualization techniques, draining away the waters of 162 00:13:35,133 --> 00:13:39,433 the Gulf of Mexico exposes an extraordinary underwater world, 163 00:13:40,567 --> 00:13:44,133 normally hidden in the dark depths of the ocean. 164 00:13:45,667 --> 00:13:50,700 But how did an accident here cause the worst environmental disaster in the history of the 165 00:13:50,733 --> 00:13:52,967 Gulf of Mexico? 166 00:13:56,300 --> 00:14:01,367 Pumpjacks like these, introduced in the 1920s, can only extract oil in very small 167 00:14:02,067 --> 00:14:04,833 quantities, on land. 168 00:14:05,167 --> 00:14:09,833 DAVE: An old well like this is perhaps producing only 10 barrels per day of oil. 169 00:14:11,800 --> 00:14:14,400 This is old technology. 170 00:14:14,433 --> 00:14:17,133 This is on the twilight of an oil field. 171 00:14:17,167 --> 00:14:19,933 You can tell that because it's nodding up and down. 172 00:14:19,967 --> 00:14:23,733 That means that the pressure in that reservoir down there is low. 173 00:14:24,100 --> 00:14:26,667 It's about ready to be finished. 174 00:14:27,000 --> 00:14:31,767 NARRATOR: In the 1940s, oil companies discover a far more productive source, 175 00:14:31,800 --> 00:14:34,633 below the waters of the Gulf of Mexico. 176 00:14:35,433 --> 00:14:38,033 Here, the oil doesn't need to be pumped. 177 00:14:38,067 --> 00:14:40,200 It flows. 178 00:14:40,233 --> 00:14:44,267 And the reason lies deeply embedded in the unique geology of the Gulf. 179 00:14:45,067 --> 00:14:49,400 JAMES: The Gulf of Mexico is one of the more oil rich areas on the planet because out beyond 180 00:14:49,433 --> 00:14:52,400 us was once an ancient swamp 300 million years ago. 181 00:14:54,667 --> 00:14:58,300 That swamp now is not only under the water, it's underneath the earth. 182 00:14:58,333 --> 00:15:02,500 And as a result of pressure and heat all of that organic material has been 183 00:15:02,533 --> 00:15:05,433 transformed into oil. 184 00:15:05,467 --> 00:15:09,333 NARRATOR: To produce an oil field, three things are essential. 185 00:15:09,367 --> 00:15:12,533 A layer of kerogen, the organic compound which creates oil. 186 00:15:13,800 --> 00:15:18,400 A permeable rock such as sandstone known as 'source rock' for the oil 187 00:15:18,867 --> 00:15:21,200 to accumulate in. 188 00:15:21,233 --> 00:15:25,900 And a trap: a layer of impermeable rock above, to prevent the oil dissipating. 189 00:15:26,867 --> 00:15:31,433 By drilling down through this hard layer, it's possible to extract the oil and gas from 190 00:15:31,800 --> 00:15:34,233 the reservoir below. 191 00:15:34,500 --> 00:15:37,933 And the Gulf's continental shelf provides the perfect base for 192 00:15:37,967 --> 00:15:40,667 offshore drilling platforms. 193 00:15:42,133 --> 00:15:46,167 -When you look out over the Gulf of Mexico and you see this flat expanse of water, 194 00:15:46,200 --> 00:15:49,167 most people don't realize that this is very shallow. 195 00:15:49,200 --> 00:15:54,100 You can go 50 to 100 miles out but it's only 100 feet deep. 196 00:15:55,133 --> 00:15:58,733 NARRATOR: Since the first platform was constructed just a mile offshore, 197 00:15:58,767 --> 00:16:01,533 the network has expanded greatly. 198 00:16:01,567 --> 00:16:05,500 Around 3,500 platforms now sit off the coast. 199 00:16:07,867 --> 00:16:12,267 But it's only by draining the ocean that it's possible to see the sheer scale of the 200 00:16:12,300 --> 00:16:15,067 infrastructure hidden beneath the waves. 201 00:16:16,033 --> 00:16:20,133 As the water recedes, these huge structures are left high and dry. 202 00:16:21,833 --> 00:16:26,100 There are more oil platforms here than in the rest of the world combined. 203 00:16:28,000 --> 00:16:33,333 In the 1970s companies begin to move off the continental shelf into ever deeper waters 204 00:16:34,033 --> 00:16:37,567 to tap into even bigger reserves. 205 00:16:37,600 --> 00:16:42,933 Operating in the Gulf's very deepest regions, up to 10,000 feet below the waves, 206 00:16:42,967 --> 00:16:46,000 where conditions are extremely hostile. 207 00:16:47,833 --> 00:16:49,933 DAVE: It is completely black. 208 00:16:49,967 --> 00:16:53,500 Temperature down there is just above freezing. 209 00:16:54,700 --> 00:16:59,733 You're drilling another sometimes 20,000 feet below the seabed and it gets 210 00:16:59,767 --> 00:17:02,233 extremely hot. 211 00:17:02,267 --> 00:17:06,533 So you have this big contrast between something that's very hot to something that's very 212 00:17:06,567 --> 00:17:09,533 cold, let alone the extremely high pressures that we have. 213 00:17:11,100 --> 00:17:15,000 NARRATOR: Today, there are around 50 deep-water rigs sited in the Gulf. 214 00:17:17,667 --> 00:17:23,500 Continuing to drain its waters beyond the continental shelf reveals the huge scale of 215 00:17:24,167 --> 00:17:28,700 infrastructure needed to bring oil to the surface from these super-deep wells. 216 00:17:30,500 --> 00:17:35,533 Clusters of well-heads control the flow of oil and gas from deep below the sea bed. 217 00:17:36,200 --> 00:17:40,267 The pressure in the wells can reach up to 22,000 pounds per square inch. 218 00:17:42,833 --> 00:17:47,900 The well-heads connect to a central manifold, up to 100 feet high, 219 00:17:47,933 --> 00:17:51,533 which controls the flow of oil and gas from across the oil field up 220 00:17:51,567 --> 00:17:54,200 to the production rig. 221 00:17:54,233 --> 00:18:00,233 The rig separates the oil and gas before they're transported to shore by pipeline some 222 00:18:00,267 --> 00:18:04,167 stretching for hundreds of miles as they wind their way along the sea bed. 223 00:18:05,833 --> 00:18:10,900 An incredible 43,000 miles of pipeline snakes across the floor of the Gulf. 224 00:18:13,667 --> 00:18:18,333 With oil reserves close to shore now becoming depleted, companies continue to search 225 00:18:18,367 --> 00:18:22,533 the Gulf of Mexico for new, more productive oil fields. 226 00:18:23,100 --> 00:18:27,600 Special rigs, costing nearly half a million dollars a day to operate, 227 00:18:28,167 --> 00:18:33,367 drill exploration wells called wildcats, reaching miles below the sea bed. 228 00:18:34,167 --> 00:18:37,967 One such rig is called the Deepwater Horizon. 229 00:18:38,600 --> 00:18:42,800 DAVE: The Deepwater Horizon is an exploration drilling rig. 230 00:18:42,833 --> 00:18:48,200 We use what we call mobile drilling units to come in and drill the initial well. 231 00:18:49,667 --> 00:18:55,500 If we find oil we run casing down there we cement it off and then we move that 232 00:18:55,533 --> 00:19:00,800 exploration rig off location and then come back later to put on 233 00:19:00,833 --> 00:19:03,033 the production equipment. 234 00:19:04,200 --> 00:19:09,100 NARRATOR: In 2010, the Deepwater Horizon strikes oil 50 miles off the coast of 235 00:19:09,133 --> 00:19:12,233 Louisiana in an area codenamed Macondo. 236 00:19:13,333 --> 00:19:18,833 -In theory that well should have been easy in that the water depth 237 00:19:19,433 --> 00:19:21,367 about 5000 feet. 238 00:19:21,400 --> 00:19:25,000 We have been drilling in 5000 feet of water since 1979. 239 00:19:25,700 --> 00:19:28,400 The pressure wasn't too high either. 240 00:19:28,433 --> 00:19:32,100 However, we are in a very potentially dangerous industry. 241 00:19:37,733 --> 00:19:40,733 REPORTER (over TV): Now another major story developing in the Gulf of Mexico. 242 00:19:40,767 --> 00:19:44,900 Eleven people are missing after an explosion and fire on an off-shore oil rig. 243 00:19:45,800 --> 00:19:48,967 REPORTER 2 (over TV): The explosion happened aboard a mobile offshore 244 00:19:49,000 --> 00:19:50,600 drilling unit called the Deepwater Horizon. 245 00:19:50,633 --> 00:19:55,000 It erupted with 126 people on board. 246 00:19:55,033 --> 00:19:59,533 NARRATOR: The cement lining, designed to seal the well before the rig moves away, 247 00:19:59,567 --> 00:20:04,067 has a leak in it allowing oil and gas to force their way up to the rig and ignite. 248 00:20:06,800 --> 00:20:09,167 After burning for two days, the rig sinks. 249 00:20:11,433 --> 00:20:14,533 The eleven missing workers are never found. 250 00:20:16,967 --> 00:20:22,533 In the aftermath, 60,000 barrels of oil per day escape into the Gulf. 251 00:20:26,067 --> 00:20:30,267 With the well-head a mile underwater and the oil pressure so high, 252 00:20:30,300 --> 00:20:33,133 engineers can't stop the flow. 253 00:20:35,033 --> 00:20:41,100 -In the immediate aftermath of the disaster even while the well was flowing the 254 00:20:41,133 --> 00:20:46,933 government stopped all deep-water drilling in the Gulf of Mexico and rightly so 255 00:20:46,967 --> 00:20:53,000 until we could figure out what had happened and what you need to do to be sure not only it 256 00:20:53,467 --> 00:20:57,233 doesn't happen again but if it does happen that you have equipment so 257 00:20:57,267 --> 00:21:00,100 that you can stop it immediately. 258 00:21:01,367 --> 00:21:06,533 NARRATOR: To seal the Macondo well, engineers design a solution from scratch... 259 00:21:06,967 --> 00:21:11,367 a capping stack to latch over the well-head, working remotely at incredible depths. 260 00:21:13,400 --> 00:21:19,900 By the time the well is sealed 87 days after the blowout, nearly 5 million barrels of 261 00:21:19,933 --> 00:21:23,567 crude oil have escaped. 262 00:21:24,267 --> 00:21:28,200 The worst environmental disaster ever to strike the Gulf of Mexico. 263 00:21:32,500 --> 00:21:35,933 The wreck of the Deepwater Horizon now lies on the sea bed. 264 00:21:38,467 --> 00:21:40,900 But it's not alone. 265 00:21:40,933 --> 00:21:45,267 Human commerce began in the Gulf of Mexico hundreds of years before the oil and gas 266 00:21:45,300 --> 00:21:48,033 industry took hold. 267 00:21:48,067 --> 00:21:52,800 As the water continues to drain away, an extraordinary relic of the region's maritime 268 00:21:53,367 --> 00:21:58,333 history is about to be revealed from a time when the Gulf became a superhighway for 269 00:21:59,633 --> 00:22:03,633 pirates and smugglers trading in the most valuable 'commodity' of the age... 270 00:22:04,367 --> 00:22:06,067 human life. 271 00:22:12,500 --> 00:22:16,233 NARRATOR: Oil and gas exploration means the seabed of the Gulf of Mexico is 272 00:22:16,267 --> 00:22:18,700 surveyed in fine detail. 273 00:22:24,533 --> 00:22:29,200 And the search for oil regularly uncovers long-lost shipwrecks. 274 00:22:30,433 --> 00:22:35,433 Including a mysterious ship 150 miles south of New Orleans. 275 00:22:38,367 --> 00:22:41,933 As the water of the Gulf of Mexico continues to drain away, 276 00:22:42,467 --> 00:22:46,500 it will be exposed to the sky for the first time in 200 years, 277 00:22:47,633 --> 00:22:52,167 giving an extraordinary insight into a period renowned for piracy, 278 00:22:52,200 --> 00:22:54,833 smuggling and slavery. 279 00:22:55,733 --> 00:23:00,067 Who was on this mysterious ship and what was its cargo? 280 00:23:03,767 --> 00:23:07,433 Sitting at the mouth of the great Mississippi River, New Orleans, 281 00:23:07,467 --> 00:23:11,233 in the early 19th century, expands rapidly. 282 00:23:12,133 --> 00:23:14,667 FREDERICK: New Orleans was basically a bustling maritime entrepôt. 283 00:23:14,700 --> 00:23:17,767 I mean, this was one of the largest ports in the western hemisphere and 284 00:23:17,800 --> 00:23:20,833 it was situated centrally in the Gulf of Mexico. 285 00:23:20,867 --> 00:23:24,233 And so, you have hundreds of ships coming and going, importing, 286 00:23:24,267 --> 00:23:26,633 exporting all sorts of different kinds of trade goods, 287 00:23:26,667 --> 00:23:31,400 but you're also seeing an increase in illicit activity from slave trade to smuggling, 288 00:23:32,300 --> 00:23:35,267 and, and this place is just booming. 289 00:23:35,733 --> 00:23:39,600 NARRATOR: Hard evidence of this extraordinary period of maritime history 290 00:23:39,633 --> 00:23:41,467 is extremely rare. 291 00:23:43,900 --> 00:23:49,367 Then, in 2011, an oil company identifies a wreck, giving it the name 'The Monterrey'. 292 00:23:51,100 --> 00:23:53,167 FREDRICK: This particular shipwreck lies on the sea floor at an approximate 293 00:23:53,200 --> 00:23:55,567 depth of 4500 feet or almost a mile, 294 00:23:56,400 --> 00:24:00,500 which makes it really difficult to get to, but it also means it's going 295 00:24:00,533 --> 00:24:03,667 to be that much better preserved because the temperature at that depth is 296 00:24:03,700 --> 00:24:06,633 four degrees Celsius and that really slows the rate of decomposition. 297 00:24:08,567 --> 00:24:12,567 NARRATOR: The team launch a state of the art remotely operated vehicle, 298 00:24:12,600 --> 00:24:14,867 or ROV, to investigate. 299 00:24:15,833 --> 00:24:18,267 FREDRICK: The ROV takes four hours to get down to the sea floor 300 00:24:18,300 --> 00:24:21,633 and so, you know, there's this anticipation. 301 00:24:24,333 --> 00:24:29,500 When the ROV hits the floor and cruises up to this particular site and we lay our 302 00:24:29,533 --> 00:24:33,300 eyes on the shipwreck for the first time, we're astounded, we're excited. 303 00:24:34,700 --> 00:24:38,967 Because what we're looking at is a largely intact ship almost a mile deep in the 304 00:24:39,000 --> 00:24:42,833 Gulf of Mexico and it was just mind-blowing. 305 00:24:43,567 --> 00:24:48,433 NARRATOR: As the ROV travels over the wreck it sends back tantalizing glimpses 306 00:24:48,467 --> 00:24:51,000 of the ship and its contents. 307 00:24:51,267 --> 00:24:54,500 -At this depth in the ocean it's pitch black, there's no light, 308 00:24:54,533 --> 00:24:57,267 you can't see anything unless you light it up. 309 00:24:57,300 --> 00:25:02,567 So, when we're working on sites like this in particular, we're only getting snapshots 310 00:25:03,567 --> 00:25:06,700 or small glimpses of the site itself. 311 00:25:07,267 --> 00:25:10,800 We don't have the entire picture while we're viewing the ROV footage. 312 00:25:14,300 --> 00:25:18,333 NARRATOR: The ROV also captures precise data from on-board sonar equipment. 313 00:25:21,267 --> 00:25:26,633 Combining this with the latest visualization techniques, it's now possible to drain 314 00:25:26,667 --> 00:25:33,233 the ocean and pull the plug on more of the Gulf of Mexico, letting archaeologists view 315 00:25:33,267 --> 00:25:37,367 the wreck from any angle and examine it in unexpected detail. 316 00:25:39,333 --> 00:25:45,533 Will seeing it for the first time in 200 years help them discover what it was doing, 317 00:25:45,567 --> 00:25:50,800 how it came to lie on the sea bed and the biggest mystery of all: who was on board. 318 00:25:53,000 --> 00:25:56,767 As the water recedes, the ship is revealed. 319 00:25:57,800 --> 00:26:00,700 The bow, sheathed in copper to protect against 320 00:26:00,733 --> 00:26:05,600 marine organisms, still intact and the anchor still stowed. 321 00:26:08,567 --> 00:26:13,700 Chain plates, once used to secure the rigging, indicate it had two wooden masts, 322 00:26:14,933 --> 00:26:17,700 long lost to the ocean. 323 00:26:18,033 --> 00:26:22,967 With the water gone, six cannon lay exposed to the sky. 324 00:26:23,500 --> 00:26:28,067 And around the stern, lying on the sea floor, a cache of muskets. 325 00:26:35,167 --> 00:26:38,633 JAMES: What struck me was this was a ship that was very long and narrow 326 00:26:39,133 --> 00:26:41,333 particularly at the bow. 327 00:26:41,367 --> 00:26:44,967 It struck me as almost being like a clipper ship, a specific type of vessel that 328 00:26:45,000 --> 00:26:48,633 came into the fore really in the early 1800s. 329 00:26:50,400 --> 00:26:53,500 NARRATOR: Clippers were perfectly suited to the Gulf of Mexico due to 330 00:26:53,533 --> 00:26:55,600 their shallow draft, 331 00:26:55,633 --> 00:26:59,167 ideal for navigating the Gulf's coastal waters and marshy bayou. 332 00:27:00,300 --> 00:27:02,833 -What also struck us was that it was armed. 333 00:27:02,867 --> 00:27:06,867 It had cannon, and there were muskets, was it a warship, was it something else? 334 00:27:07,933 --> 00:27:10,533 NARRATOR: Is it a privateer? 335 00:27:10,567 --> 00:27:14,700 -A privateer is basically an individual that has written permission or letter of marque 336 00:27:14,733 --> 00:27:20,533 or letter of commission from a respective government giving them permissions to capture 337 00:27:20,567 --> 00:27:26,067 ships, to make incursions on enemy soil in the name of that particular country. 338 00:27:26,900 --> 00:27:31,633 -Privateering is basically state sponsored piracy, in which the privateer gets a cut 339 00:27:31,667 --> 00:27:34,467 of the action and the rest goes to the state that's licensed them. 340 00:27:36,333 --> 00:27:40,467 NARRATOR: In the first two decades of the 19th century there are hundreds 341 00:27:40,500 --> 00:27:42,967 of privateers in the Gulf of Mexico. 342 00:27:44,000 --> 00:27:48,100 But as the ocean drains even further away from around the Monterrey, 343 00:27:48,600 --> 00:27:51,000 there's a twist to this story. 344 00:27:51,033 --> 00:27:53,800 The wreck is not alone. 345 00:27:54,633 --> 00:28:00,133 As the water disappears, a complete picture of the entire sea floor begins to emerge for 346 00:28:00,167 --> 00:28:03,633 the very first time, revealing the remains of two other ships, 347 00:28:05,200 --> 00:28:08,033 each containing further clues. 348 00:28:08,067 --> 00:28:12,400 -It's really exciting to have one shipwreck but when all of a sudden you go from one to 349 00:28:12,867 --> 00:28:18,033 three it gets incrementally more exciting because now we're not talking about just 350 00:28:18,067 --> 00:28:21,233 one wreck we're talking about a potential convoy. 351 00:28:22,633 --> 00:28:27,300 NARRATOR: Wreck A, the first ship discovered, is heavily armed with cannon and muskets 352 00:28:27,967 --> 00:28:32,633 for close quarter combat, leaving researchers to think it could be a privateer. 353 00:28:33,733 --> 00:28:38,033 With wreck B, it's clear that the wooden hull has been consumed by the ocean. 354 00:28:39,867 --> 00:28:43,433 But its cargo is still intact. 355 00:28:43,767 --> 00:28:48,967 It's carrying animal hides, a valuable commodity at the time and frequently traded. 356 00:28:50,033 --> 00:28:55,100 Treated and rolled for shipment, they are well preserved by the cold waters. 357 00:28:55,667 --> 00:29:01,033 Wreck C, exposed to the sky for the first time in 200 years, is a larger, 358 00:29:01,067 --> 00:29:03,200 three-masted vessel. 359 00:29:03,233 --> 00:29:07,267 But amongst this wreck, there's no cargo to be found. 360 00:29:07,567 --> 00:29:09,533 -What does that mean? 361 00:29:09,567 --> 00:29:12,367 Well it means the ship was either sailing in ballast, that is empty, 362 00:29:12,400 --> 00:29:16,267 or it had a cargo that was perishable, and that perishable cargo could have 363 00:29:16,300 --> 00:29:22,600 been everything from rice or grain, to one possibility being a very sobering thought 364 00:29:22,633 --> 00:29:25,433 and that is it could have been carrying people. 365 00:29:25,467 --> 00:29:28,700 It may have been a vessel engaged in the illegal slave trade. 366 00:29:29,900 --> 00:29:34,300 NARRATOR: The trans-Atlantic slave trade sees slaves violently captured and 367 00:29:34,333 --> 00:29:37,933 shipped from West Africa, and then forced to work on US plantations. 368 00:29:40,267 --> 00:29:45,300 Although owning slaves remains lawful, the import of new ones is outlawed by 369 00:29:45,333 --> 00:29:47,933 Congress in 1807. 370 00:29:49,000 --> 00:29:54,000 Great Britain also bans the trade and uses its navy to hunt down and 371 00:29:54,033 --> 00:29:56,600 capture slave ships. 372 00:29:56,933 --> 00:29:59,533 With much money still to be made, 373 00:29:59,567 --> 00:30:03,200 smugglers continue to bring captured African men, 374 00:30:03,233 --> 00:30:08,833 women and children through the Gulf of Mexico and into its maze of channels and 375 00:30:08,867 --> 00:30:12,333 waterways, aiming for New Orleans and its slave markets. 376 00:30:12,833 --> 00:30:17,167 Is wreck C involved in this brutal, callous business? 377 00:30:17,500 --> 00:30:21,700 -Now we didn't see manacles or anything of that sort but in this period, when it's lost, 378 00:30:21,733 --> 00:30:25,567 it's entirely possible, as we know from other cases, that people were simply locked 379 00:30:25,600 --> 00:30:29,667 below in the hold, and with those that were most capable of trying to escape 380 00:30:29,700 --> 00:30:32,333 being tied up. 381 00:30:33,800 --> 00:30:36,767 NARRATOR: The team begin to piece together the evidence. 382 00:30:36,800 --> 00:30:40,800 -In thinking about these ships as a convoy, we can hypothesize a 383 00:30:40,833 --> 00:30:43,333 variety of scenarios. 384 00:30:43,367 --> 00:30:47,267 The first would be it's an armed escort with two merchant ships that need protection to 385 00:30:47,300 --> 00:30:50,067 get from one port to another. 386 00:30:50,100 --> 00:30:54,567 It could be a privateer with two prizes that it captured. 387 00:30:54,600 --> 00:30:59,700 In looking at the cargo on the second ship we have stacks and stacks of cow hides. 388 00:31:01,333 --> 00:31:04,667 Those would have brought a great price at the market, even if you were smuggling. 389 00:31:06,967 --> 00:31:11,100 NARRATOR: To unravel the mystery further, they select a range of artifacts and bring 390 00:31:11,133 --> 00:31:13,800 them to the surface. 391 00:31:18,833 --> 00:31:22,033 They could reveal once and for all who was on board. 392 00:31:23,000 --> 00:31:26,267 AMY: One of the unique things about this particular shipwreck Monterrey shipwreck-A 393 00:31:26,300 --> 00:31:30,000 was the cannons and the presence of muskets. 394 00:31:30,333 --> 00:31:33,067 Those were all British types, British military musket types. 395 00:31:33,100 --> 00:31:36,067 They were absolutely ubiquitous in this region during the first half of the 396 00:31:36,100 --> 00:31:39,700 19th century, so having British muskets on a ship does not mean that it's 397 00:31:39,733 --> 00:31:41,633 a British vessel. 398 00:31:41,667 --> 00:31:44,833 NARRATOR: The crews' nationality remains a mystery. 399 00:31:44,867 --> 00:31:48,800 But there are other clues that may tell us what caused the ships to sink. 400 00:31:49,400 --> 00:31:53,167 AMY: A portion of the collection that was recovered were navigational tools. 401 00:31:53,200 --> 00:31:57,400 The importance of these tools was so great that you would have wanted to have taken 402 00:31:57,433 --> 00:32:01,833 those with you so leaving them on the ship is foreboding and you know, 403 00:32:01,867 --> 00:32:04,167 it suggests that maybe everyone perished. 404 00:32:06,167 --> 00:32:10,600 NARRATOR: The Gulf of Mexico is notorious for a particularly violent force of 405 00:32:10,633 --> 00:32:14,600 nature: hurricanes, giving rise to one likely scenario. 406 00:32:16,667 --> 00:32:19,533 JAMES: All three of them were running together in what clearly was a 407 00:32:19,567 --> 00:32:22,300 very violent storm. 408 00:32:22,333 --> 00:32:25,933 You had a quick moment to look on the horizon, see the other guys there and 409 00:32:25,967 --> 00:32:28,900 then their lights disappear if it's at night or they disappear in a squall. 410 00:32:29,500 --> 00:32:33,767 And the next thing you know the Gulf is coming over your own decks and you're being 411 00:32:33,800 --> 00:32:36,533 dragged down into the depths, and into the darkness. 412 00:32:37,733 --> 00:32:41,533 NARRATOR: The Monterrey group of wrecks provides a new insight into the maritime 413 00:32:41,567 --> 00:32:44,133 history of the Gulf of Mexico, 414 00:32:44,167 --> 00:32:47,033 at a turning point in US history. 415 00:32:47,067 --> 00:32:50,300 FREDRICK: The Monterey shipwrecks are important because they're evidence of that 416 00:32:50,333 --> 00:32:51,867 transition to the birth of a new nation. 417 00:32:51,900 --> 00:32:54,867 How trade continued while the Spanish empire crumbled. 418 00:32:54,900 --> 00:32:58,200 Why New Orleans was such an important part of this interregional, 419 00:32:58,233 --> 00:33:00,700 burgeoning global trade. 420 00:33:00,733 --> 00:33:04,333 And that's what those shipwrecks speak to and that's what they're symbolic of. 421 00:33:06,600 --> 00:33:09,867 NARRATOR: The Monterrey wrecks are not alone. 422 00:33:10,167 --> 00:33:13,767 As the water drains away further, leaving the darkest depths of the 423 00:33:13,800 --> 00:33:16,267 Gulf of Mexico exposed, 424 00:33:16,300 --> 00:33:20,433 one of the most extraordinary stories of all is about to be revealed: 425 00:33:21,367 --> 00:33:26,100 a state-of-the-art WW2 submarine, not American but German. 426 00:33:27,100 --> 00:33:32,000 What was Nazi submarine U-166 doing in the Gulf of Mexico? 427 00:33:32,467 --> 00:33:35,067 And how did it meet its end? 428 00:33:40,833 --> 00:33:46,167 * 429 00:33:47,367 --> 00:33:49,900 NARRATOR: December 11, 1941. 430 00:33:50,833 --> 00:33:53,800 Hitler declares war on the United States. 431 00:34:10,500 --> 00:34:14,067 NARRATOR: When the US enters the war, a new battleground opens up... 432 00:34:14,733 --> 00:34:17,267 The Gulf of Mexico. 433 00:34:17,833 --> 00:34:22,733 Today, by draining away its dark waters, it's possible to reveal secrets from this 434 00:34:23,300 --> 00:34:29,067 desperate period of conflict, when a ruthless battle to rule the waves comes to America's 435 00:34:29,100 --> 00:34:35,633 own shores and solve a mystery which has baffled historians for over 70 years. 436 00:34:41,333 --> 00:34:45,767 Immediately after entering World War II, the US faces a deadly peril, 437 00:34:45,800 --> 00:34:48,800 off its eastern seaboard. 438 00:34:48,833 --> 00:34:51,500 Nazi U-boats. 439 00:34:53,867 --> 00:34:58,967 Their objective is to disrupt Allied shipping bound for Europe, at the source. 440 00:35:00,033 --> 00:35:04,300 The U-boat commanders are highly experienced, having honed their skills 441 00:35:04,333 --> 00:35:06,667 in battle since 1939. 442 00:35:07,400 --> 00:35:11,367 The United States is completely unprepared for them. 443 00:35:11,833 --> 00:35:16,167 ERIC: Ships were escorted across the North Atlantic in convoys both ways. 444 00:35:16,200 --> 00:35:17,600 But once they got into American coastal waters they were unescorted, 445 00:35:17,633 --> 00:35:23,100 and they were therefore easy targets for the U-boats. 446 00:35:23,133 --> 00:35:27,333 NARRATOR: To make matters worse, the US government fails to impose a blackout. 447 00:35:27,367 --> 00:35:31,233 Ships sailing along the coast at night are perfectly silhouetted. 448 00:35:31,267 --> 00:35:32,900 Sitting ducks. 449 00:35:33,433 --> 00:35:35,167 -And this was a key vulnerability the Germans noticed, 450 00:35:35,200 --> 00:35:38,267 and they sent their submarines in to exploit it. 451 00:35:40,233 --> 00:35:44,667 NARRATOR: German submarine commanders call it 'American shooting season'. 452 00:35:47,000 --> 00:35:52,500 Between January and June 1942, more tonnage is sunk off the U.S. 453 00:35:52,533 --> 00:35:57,767 coast than the Allies have lost during the previous two and a half years, 454 00:35:57,800 --> 00:36:01,233 as the Nazis try to starve Britain of vital supplies. 455 00:36:02,533 --> 00:36:05,867 The U Boats then take the war into the Gulf of Mexico. 456 00:36:09,700 --> 00:36:12,500 And the reason is oil. 457 00:36:13,067 --> 00:36:16,567 -Most of the world's oil at this time came through the Gulf of Mexico, 458 00:36:16,600 --> 00:36:20,533 hence it was the equivalent to the Arabian Gulf today. 459 00:36:22,533 --> 00:36:24,900 NARRATOR: It's not just oil tankers. 460 00:36:24,933 --> 00:36:28,333 Any Allied ship is seen as fair game. 461 00:36:28,367 --> 00:36:31,533 JAMES: A U-boat skipper did not want to pass up on the opportunity to sink what might 462 00:36:31,567 --> 00:36:35,267 be a valuable cargo of a specific commodity, be it foodstuffs, 463 00:36:35,300 --> 00:36:37,633 be it machinery or parts. 464 00:36:37,667 --> 00:36:41,133 He couldn't know for certain, but he did know that if he sent a ship to the bottom he 465 00:36:41,167 --> 00:36:43,200 was aiding the German war effort. 466 00:36:43,900 --> 00:36:46,900 NARRATOR: One such ship is the Robert E Lee. 467 00:36:47,400 --> 00:36:49,933 ROB: The Robert E. Lee was a passenger freighter. 468 00:36:49,967 --> 00:36:55,167 It was coming from Trinidad up to New Orleans and it actually was carrying American 469 00:36:55,200 --> 00:37:00,600 construction workers and also a lot of other passengers that were victims 470 00:37:00,633 --> 00:37:02,367 on previous U-Boat sinking's. 471 00:37:05,133 --> 00:37:08,233 NARRATOR: As the Robert E Lee approaches New Orleans, 472 00:37:08,267 --> 00:37:11,367 U-166 is on patrol. 473 00:37:11,400 --> 00:37:18,000 One of the latest German long-range submarines, U-166 is capable of traveling across 474 00:37:18,033 --> 00:37:21,767 the Atlantic without the need to refuel. 475 00:37:22,067 --> 00:37:28,633 A thoroughbred ocean predator, commanded by battle-hardened Captain Hans Gunther Kuhlmann. 476 00:37:28,667 --> 00:37:32,167 ROB: Hans Gunther Kuhlmann had not had a lot of success during this mission. 477 00:37:32,200 --> 00:37:36,867 He had sank a couple of small boat, including one that was just a few tons. 478 00:37:36,900 --> 00:37:40,200 It actually bore the same name of his wife, Gertrude. 479 00:37:40,233 --> 00:37:46,167 And so as soon as he saw a large vessel over 5,000 tons, it was a big target and it was 480 00:37:46,200 --> 00:37:49,133 an opportunity for him to get some tonnage under his belt. 481 00:37:51,167 --> 00:37:55,267 NARRATOR: The details of the battle, including the fate of U-166, 482 00:37:55,300 --> 00:37:59,833 for years remain one of the Gulf of Mexico's greatest mysteries. 483 00:38:00,433 --> 00:38:05,667 Rob Church is a marine archaeologist for a company performing surveys of the 484 00:38:05,700 --> 00:38:08,467 sea floor for the oil and gas industry. 485 00:38:08,500 --> 00:38:13,467 When a wreck is discovered, his job is to assess its historical importance. 486 00:38:13,500 --> 00:38:16,567 -So, this is a typical inspection class ROV. 487 00:38:16,600 --> 00:38:18,500 It is a 3,000-meter rated system. 488 00:38:18,533 --> 00:38:20,400 On this particular one right now we have three camera arrays here. 489 00:38:20,433 --> 00:38:23,467 We have the two stereo cameras for collecting 3D video. 490 00:38:23,500 --> 00:38:28,433 We have the HD camera above them for collecting high resolution video. 491 00:38:28,467 --> 00:38:32,400 We also have a seven-function manipulator arm which allows us to be able to pick up 492 00:38:32,433 --> 00:38:37,633 things on the sea floor; collect samples, also ah set out experiments, etcetera. 493 00:38:37,667 --> 00:38:40,500 And then we have a scanning sonar. 494 00:38:40,533 --> 00:38:45,000 This allows us to detect targets on the sea floor to inspect or we can also use it 495 00:38:45,033 --> 00:38:46,567 navigate around shipwrecks. 496 00:38:48,833 --> 00:38:52,967 NARRATOR: While conducting an oil pipeline survey using an ROV similar to this, 497 00:38:53,000 --> 00:38:55,833 Rob Church comes across a wreck. 498 00:38:57,033 --> 00:38:59,400 ROB: We approached from the stern and you could see the railing, 499 00:38:59,433 --> 00:39:01,700 you could see the decks of that passenger freighter 500 00:39:01,733 --> 00:39:04,100 and there was no doubt at that point that we were looking at the Robert E. Lee. 501 00:39:05,767 --> 00:39:07,367 This was a thrilling moment. 502 00:39:07,400 --> 00:39:10,933 And to see a boat like the Robert E. Lee, 503 00:39:10,967 --> 00:39:14,300 which is really a beautiful wreck site, it was incredible. 504 00:39:19,000 --> 00:39:25,367 NARRATOR: Over 5,000 feet down, the ROV scans the site collecting valuable data. 505 00:39:28,967 --> 00:39:34,033 From this, it's possible to drain away the ocean and see the drowned vessel as she is 506 00:39:34,067 --> 00:39:39,167 today but this time, exposed to the sunlight. 507 00:39:41,867 --> 00:39:47,100 As the water pours away, the wreck of the Robert E Lee is revealed in extraordinary 508 00:39:47,133 --> 00:39:51,533 detail, providing new evidence on her final moments. 509 00:39:53,633 --> 00:39:59,367 The bridge is gone, unable to withstand the forces of drag as the ship plummeted 510 00:39:59,400 --> 00:40:00,767 through the water. 511 00:40:03,033 --> 00:40:08,267 The deck gun on the stern is in the stored position showing the attack 512 00:40:08,300 --> 00:40:10,600 is sudden and unexpected. 513 00:40:12,000 --> 00:40:15,867 And lying next to the wreck are two lifeboats. 514 00:40:16,400 --> 00:40:22,100 The speed with which the ship goes down does not give the crew time to deploy them. 515 00:40:22,500 --> 00:40:27,600 Experts calculate that it takes just three minutes for the Robert E Lee to sink. 516 00:40:28,267 --> 00:40:32,467 But one important part of the puzzle remains unanswered. 517 00:40:32,500 --> 00:40:37,733 What happened to the U-boat that fired the deadly torpedo? 518 00:40:37,767 --> 00:40:42,400 As the water continues to drain away from the wreck of the Robert E Lee, 519 00:40:42,733 --> 00:40:46,800 one of the Gulf of Mexico's biggest maritime mysteries is about to be solved. 520 00:40:58,067 --> 00:41:00,833 NARRATOR: July 30, 1942. 521 00:41:02,833 --> 00:41:08,667 The German submarine U-166 fires a fatal shot at the merchant vessel, 522 00:41:08,700 --> 00:41:12,300 Robert E. Lee off the coast of New Orleans. 523 00:41:13,933 --> 00:41:17,133 It sinks in three minutes. 524 00:41:17,167 --> 00:41:20,267 But the Robert E Lee is not alone. 525 00:41:20,733 --> 00:41:28,033 It's escorted by a submarine chaser Patrol Craft 566, captained by Herbert Claudius. 526 00:41:28,400 --> 00:41:32,200 ROB: The indications are that the U-Boat had no idea that the patrol craft was 527 00:41:32,233 --> 00:41:34,267 bearing down on them. 528 00:41:34,300 --> 00:41:35,800 They were proceeding at periscope depth watching the 529 00:41:35,833 --> 00:41:38,067 Robert E. Lee sink. 530 00:41:38,100 --> 00:41:42,067 It wasn't until the patrol craft got within range and began actively pinging sonar 531 00:41:42,100 --> 00:41:45,367 against the hull that they first apparently realized they were under attack at that 532 00:41:45,400 --> 00:41:49,767 moment and began to dive. 533 00:41:50,100 --> 00:41:54,100 JAMES: Within very short range, the hunter becomes the hunted. 534 00:41:54,433 --> 00:41:58,133 NARRATOR: As Patrol Craft 566 passes over the U-boat, 535 00:41:58,167 --> 00:42:02,333 Captain Claudius fires two rounds of depth charges. 536 00:42:05,467 --> 00:42:10,167 Unable to confirm a kill, he turns his attention to rescuing survivors 537 00:42:10,200 --> 00:42:11,633 of the Robert E Lee. 538 00:42:12,033 --> 00:42:16,400 The fate of U-166 remains unknown. 539 00:42:17,100 --> 00:42:24,433 Two days later a US Coast Guard plane spots a U-boat surfacing 140 miles away. 540 00:42:24,467 --> 00:42:30,833 It drops a single depth charge and the U-boat disappears. 541 00:42:32,933 --> 00:42:36,767 The plane crew is credited with sinking U-166. 542 00:42:37,467 --> 00:42:40,800 But despite extensive scanning of the sea floor, 543 00:42:40,833 --> 00:42:44,200 no trace of a wreck is ever found. 544 00:42:44,633 --> 00:42:50,300 -Finding something that so many people had looked for so long it's kind of you know, 545 00:42:50,333 --> 00:42:52,667 it takes an element of luck. 546 00:42:53,267 --> 00:42:57,100 NARRATOR: Studying a sonar scan of the sea bed around the Robert E Lee, 547 00:42:57,500 --> 00:43:02,433 Church spots a mysterious object, less than two miles away from the wreck. 548 00:43:02,467 --> 00:43:06,433 ROB: So, as I first saw the image I realized it had potential. 549 00:43:06,467 --> 00:43:12,600 But it was about 50, 60 feet short of the dimensions of a Type 9C German U Boat. 550 00:43:12,633 --> 00:43:18,333 NARRATOR: What was this mysterious wreck, 140 miles away from where U-166 was 551 00:43:18,367 --> 00:43:20,933 believed to have sunk? 552 00:43:20,967 --> 00:43:23,667 Could it be the missing sub? 553 00:43:23,700 --> 00:43:27,233 Further draining of the ocean uncovers the truth. 554 00:43:27,700 --> 00:43:32,867 As the water recedes, light begins to pour onto this mystery vessel. 555 00:43:33,233 --> 00:43:39,267 The conning tower of a German U-boat gradually appears, its antenna unretracted 556 00:43:39,300 --> 00:43:43,733 indicating it dived suddenly and under duress. 557 00:43:44,100 --> 00:43:50,033 Next, its hull is exposed to the sky for the first time in over 70 years. 558 00:43:50,433 --> 00:43:55,000 The configuration of the conning tower and deck guns exactly matches 559 00:43:55,033 --> 00:43:58,167 the missing U-166. 560 00:43:58,200 --> 00:44:04,033 And from another angle, the reason the sonar image is short suddenly becomes clear. 561 00:44:04,067 --> 00:44:09,200 The U-boat's bow is missing, blown off by a massive explosion. 562 00:44:09,633 --> 00:44:14,000 As the water continues to drain away, the missing section is revealed, 563 00:44:14,033 --> 00:44:17,867 lying 500 feet away. 564 00:44:17,900 --> 00:44:23,500 A depth charge alone could not have caused such catastrophic damage. 565 00:44:24,400 --> 00:44:27,467 So, what happened? 566 00:44:27,500 --> 00:44:31,867 -It appears that after one of the depth charges breached the pressure hull that it probably 567 00:44:31,900 --> 00:44:39,167 set off an internal explosion which then ripped the bow section off. 568 00:44:39,200 --> 00:44:42,300 ERIC: When the submarine dived, perhaps torpedoes became loose and it was more 569 00:44:42,333 --> 00:44:44,367 likely that an explosion would occur. 570 00:44:44,400 --> 00:44:47,467 This was a successful depth charge attack and it was clear that this was actually 571 00:44:47,500 --> 00:44:52,300 sunk as claimed by the submarine chaser. 572 00:44:52,333 --> 00:45:00,300 NARRATOR: 22 people lost their lives on the Robert E Lee and all 52 perished on the U-166. 573 00:45:00,333 --> 00:45:05,667 The two wrecks are now considered a war grave and cannot be salvaged. 574 00:45:06,067 --> 00:45:10,000 Draining the ocean is the only way to bring the wrecks to the surface and 575 00:45:10,033 --> 00:45:14,000 in the process set the record straight. 576 00:45:14,300 --> 00:45:17,600 With the U-boat discovered lying less than two miles from the Robert E Lee, 577 00:45:17,633 --> 00:45:21,200 there can be no doubt who sank it. 578 00:45:21,233 --> 00:45:27,100 The kill is now credited to Herbert Claudius, captain of Patrol Craft 566. 579 00:45:28,000 --> 00:45:34,433 Soon after the sinking of U-166, the tide begins to turn in the Battle of the Atlantic. 580 00:45:35,133 --> 00:45:40,200 -Inevitably, the Allies were able to push back against the U-boat assault thanks 581 00:45:40,233 --> 00:45:42,700 to a variety of factors. 582 00:45:42,733 --> 00:45:47,700 Increased surveillance, more convoys, as well as the ability to strike from the air, 583 00:45:47,733 --> 00:45:50,300 the U-boats were steadily defeated. 584 00:45:54,500 --> 00:45:59,700 NARRATOR: Nevertheless, during the Second World War, while operating in US waters, 585 00:45:59,733 --> 00:46:07,200 the German navy sends 609 Allied ships to the bottom of the ocean with the loss of 586 00:46:07,233 --> 00:46:10,233 only 12 U-boats. 587 00:46:11,867 --> 00:46:17,067 Of those, only one submarine is sunk in the Gulf of Mexico... 588 00:46:17,100 --> 00:46:19,633 U-166. 589 00:46:22,433 --> 00:46:28,333 Looking below the waters of the Gulf of Mexico has solved long lost mysteries and 590 00:46:28,367 --> 00:46:35,267 brought deadly secrets back to the surface showing that the story of North America: 591 00:46:35,300 --> 00:46:41,533 through trade, war and even the death of the dinosaurs can only be fully 592 00:46:41,567 --> 00:46:46,300 seen and understood by draining the oceans. 593 00:46:47,667 --> 00:46:49,033 Captioned by Cotter Captioning Services.