1 00:00:00,000 --> 00:00:08,000 Can new discoveries finally tell us what led to one of the biggest catastrophes on the Great Lakes? 2 00:00:08,000 --> 00:00:11,000 The sinking of the mighty SS Fitzgerald. 3 00:00:11,000 --> 00:00:18,000 The highest waves were up to 25 to 30 feet, and that was exactly the place where the Fitzgerald was, 4 00:00:18,000 --> 00:00:21,000 and exactly the time they were there. 5 00:00:21,000 --> 00:00:28,000 Could newly declassified information explain a mysterious encounter between the US Navy 6 00:00:28,000 --> 00:00:32,000 and an unidentified underwater craft? 7 00:00:32,000 --> 00:00:35,000 The science we have today can't explain it. 8 00:00:35,000 --> 00:00:37,000 It has me boggled. 9 00:00:39,000 --> 00:00:45,000 And what's making one of Egypt's top diving spots one of the most deadly in the world? 10 00:00:45,000 --> 00:00:49,000 200 fatalities for a single dive site is very, very high. 11 00:00:49,000 --> 00:00:53,000 This makes it only second to Everest in terms of the dangers. 12 00:00:54,000 --> 00:00:59,000 The underwater realm is another dimension. 13 00:00:59,000 --> 00:01:08,000 It's a physically hostile place where dreams of promise can sink into darkness. 14 00:01:08,000 --> 00:01:10,000 I'm Jeremy Wade. 15 00:01:10,000 --> 00:01:17,000 I'm searching the world to bring you the most iconic and baffling underwater mysteries known to science. 16 00:01:17,000 --> 00:01:20,000 Shipwrecks can't just disappear, or can they? 17 00:01:20,000 --> 00:01:25,000 It's a dangerous unexplored frontier that swallows evidence. 18 00:01:25,000 --> 00:01:28,000 We know more about the face of Mars than we do our deepest oceans. 19 00:01:28,000 --> 00:01:34,000 Where unknown is normal and understanding is rare. 20 00:01:34,000 --> 00:01:41,000 I've been out on boats that have suddenly become caught in a storm. 21 00:01:41,000 --> 00:01:48,000 There's nothing quite as terrifying as the destructive power of wind, water and waves. 22 00:01:48,000 --> 00:01:52,000 Sometimes these forces can prove too much to be true. 23 00:01:52,000 --> 00:01:58,000 But I've been out on boats that have suddenly become caught in a storm. 24 00:01:58,000 --> 00:02:02,000 There's no wind, water and waves. 25 00:02:02,000 --> 00:02:08,000 Sometimes these forces can prove too much for even the strongest craft. 26 00:02:08,000 --> 00:02:14,000 In 1975 a devastating maritime disaster shocked the world. 27 00:02:14,000 --> 00:02:17,000 And it still has experts baffled to this day. 28 00:02:17,000 --> 00:02:25,000 But could new hydrodynamic research finally tell us what happened to the SS Edmund Fitzgerald? 29 00:02:29,000 --> 00:02:32,000 November 9, 1975. 30 00:02:32,000 --> 00:02:40,000 Freight carrier the SS Edmund Fitzgerald sets off on her regular five-day journey across Lake Superior. 31 00:02:40,000 --> 00:02:46,000 She's made more than 700 similar voyages during her career. 32 00:02:46,000 --> 00:02:53,000 The weathers calm in port, but storm warnings have been issued for a section of the lake along her route. 33 00:02:53,000 --> 00:03:01,000 These were rough conditions for smaller boats, but for a ship like the Fitzgerald, not something that was overly concerning. 34 00:03:01,000 --> 00:03:05,000 The ship's nickname is the mighty Fitz. 35 00:03:05,000 --> 00:03:12,000 At over 700 feet long she's a Leviathan, built to deal with the roughest weather. 36 00:03:12,000 --> 00:03:16,000 And she has an incredibly experienced skipper at the helm. 37 00:03:16,000 --> 00:03:22,000 Captain Ernest McSawley has been navigating the Great Lakes for most of his life. 38 00:03:22,000 --> 00:03:25,000 He is known for his mastery of the lakes. 39 00:03:25,000 --> 00:03:29,000 You don't become a captain of the largest vessel on the lake. 40 00:03:29,000 --> 00:03:32,000 By not being a good captain, he had a great reputation. 41 00:03:32,000 --> 00:03:39,000 After 44 years on the Great Lakes, McSawley is set to retire in a few weeks' time. 42 00:03:39,000 --> 00:03:45,000 Overnight, the Fitz reports increasingly stormy weather to the Coast Guard. 43 00:03:45,000 --> 00:03:51,000 The waves were increasing in height, but the waves usually didn't affect them. 44 00:03:53,000 --> 00:04:01,000 Then, at 3.30pm on November 10, the Fitzgerald makes a call to a ship travelling a few miles behind. 45 00:04:01,000 --> 00:04:05,000 McSawley reports that the Fitz has suffered some damage 46 00:04:05,000 --> 00:04:11,000 and asks the other ship to stay with them until they reach the safety of the nearest port. 47 00:04:11,000 --> 00:04:21,000 He did make a request that a ship would shadow him, which basically means that he was concerned that in case they did have to leave the ship, that there would be another ship nearby. 48 00:04:22,000 --> 00:04:28,000 The waves are now so high, they're interfering with the Fitz's radar systems. 49 00:04:28,000 --> 00:04:37,000 McSawley puts in another call to the ship that's following to ask for radar plots to help guide them into shore. 50 00:04:37,000 --> 00:04:41,000 It's clear from the communications that the captain was concerned. 51 00:04:41,000 --> 00:04:46,000 I mean, it was a big storm and they were taking on water, but he also felt that they could continue. 52 00:04:46,000 --> 00:04:51,000 He basically said that things were going fine, that she was moving along like an old shoe. 53 00:04:51,000 --> 00:04:54,000 But that was the last that anyone heard from the ship. 54 00:04:55,000 --> 00:05:04,000 At 7.15pm, just 17 miles from the safety of shore, the Fitzgerald disappears from the other ship's radar. 55 00:05:05,000 --> 00:05:10,000 They try to radio through to the Fitz, but she's gone. 56 00:05:11,000 --> 00:05:20,000 The only sign of the mighty Fitzgerald's existence is two empty lifeboats. 57 00:05:21,000 --> 00:05:25,000 There are no survivors and no eyewitnesses. 58 00:05:25,000 --> 00:05:34,000 What was it that caused such a massive ship, almost as long as the Titanic was, to sink in a lake, not in the ocean? 59 00:05:34,000 --> 00:05:38,000 One of the big mysteries is why didn't the captain send a distress call? 60 00:05:38,000 --> 00:05:40,000 He would have known he had the experience. 61 00:05:40,000 --> 00:05:47,000 He'd already reported that they were bringing on water, so it's really unusual that there was no additional distress call. 62 00:05:50,000 --> 00:05:55,000 What happened to the SS-Edmond Fitzgerald that fateful day? 63 00:05:55,000 --> 00:06:03,000 It's a mystery that has haunted the Great Lakes maritime community for half a century. 64 00:06:06,000 --> 00:06:12,000 Lake Superior is known for its quick and violent gale-force storms. 65 00:06:12,000 --> 00:06:16,000 But Captain McSawley had weathered many of these in his time. 66 00:06:17,000 --> 00:06:25,000 The event was incredibly quick because between the communications and the loss of communications was a very short period of time. 67 00:06:27,000 --> 00:06:36,000 There was no Mayday or SOS call, which is quite strange from a boat there, but it might have happened so quickly that nobody actually was able to get to the radio. 68 00:06:37,000 --> 00:06:41,000 Crews are immediately scrambled to look for the Fitzgerald. 69 00:06:42,000 --> 00:06:48,000 But hampered by bad weather, it takes four days before the ship is located using sonar. 70 00:06:50,000 --> 00:06:54,000 She's resting on the lake bed over 500 feet down. 71 00:06:56,000 --> 00:07:02,000 It's a further six months before remote underwater cameras can be deployed to take a proper look. 72 00:07:03,000 --> 00:07:06,000 No one can believe what they find. 73 00:07:07,000 --> 00:07:14,000 When they found the vessel, it was split in two, which means it usually caused by a catastrophic event. 74 00:07:16,000 --> 00:07:18,000 It's unlike anything they've seen before. 75 00:07:20,000 --> 00:07:26,000 Initially, they thought that they would find the entire hull intact, but researchers knew that it had broken up. 76 00:07:26,000 --> 00:07:29,000 The question is, why did that happen? 77 00:07:30,000 --> 00:07:38,000 For nearly half a century, no one has known for sure what caused this mighty titan of the Great Lakes to break in half. 78 00:07:39,000 --> 00:07:45,000 But can new research finally tell us what happened that fateful night? 79 00:08:00,000 --> 00:08:09,000 In November 1975, Lake Superior's largest freighter, the SS Edmund Fitzgerald, vanishes with all her crew. 80 00:08:10,000 --> 00:08:13,000 Those who find her wreck are shocked by what they see. 81 00:08:14,000 --> 00:08:18,000 From the remains at the bottom of the lake, it appears she's broken in two. 82 00:08:19,000 --> 00:08:27,000 Now, more than 40 years later, experts may be about to solve the mystery of what sank the fish. 83 00:08:30,000 --> 00:08:42,000 Lake Superior reaches depths of over 1,300 feet, but lurking just below the surface are natural ridges that are catastrophic for any ship that comes too close. 84 00:08:43,000 --> 00:08:50,000 There's a question of whether the Fitzgerald struck bottom going over some of the shoals near Carriable Island, north of where it sank. 85 00:08:51,000 --> 00:08:56,000 With his navigational tools wiped out, could the captain have smashed his ship on the shoals? 86 00:08:57,000 --> 00:09:04,000 I highly doubt a captain of McSorley's experience would have issues not knowing where shoals are. 87 00:09:05,000 --> 00:09:08,000 The official investigation blames the ship's failed hatch covers. 88 00:09:09,000 --> 00:09:16,000 Edmund Fitzgerald had 26,000 tons of ore in it. Therefore, she's going to be low in the water. 89 00:09:17,000 --> 00:09:20,000 If you have waves washing over the deck, they should wash off. 90 00:09:20,000 --> 00:09:25,000 If your hatch covers aren't dogged down properly, it's going to let water in. 91 00:09:26,000 --> 00:09:29,000 But not all experts are convinced by the hatch theory. 92 00:09:30,000 --> 00:09:35,000 I don't really believe in that because of the size of the ship. You would have to leave them open for quite a long time. 93 00:09:36,000 --> 00:09:40,000 It would be gradual. It would have to flood slowly. And this was a very sudden event. 94 00:09:41,000 --> 00:09:49,000 What's more, the ship was equipped with two powerful 7,000 gallon per minute water pumps, which were both running at the time. 95 00:09:51,000 --> 00:09:58,000 What it really looked like was that there had been a stress fracture and that the ship had broken in two. 96 00:09:59,000 --> 00:10:04,000 And then both pieces spun away from each other and eventually sank. 97 00:10:05,000 --> 00:10:10,000 Dave Schwab was a rookie scientist working on the Great Lakes when the FITs disappeared. 98 00:10:11,000 --> 00:10:21,000 When the Fitzgerald sank, no one could understand how there could be a storm bad enough to sink one of these Great Lakes freighters. 99 00:10:22,000 --> 00:10:28,000 They were designed to run through the largest waves they thought they would encounter. 100 00:10:31,000 --> 00:10:39,000 But what if they came up against the most unpredictable force that mariners can face during a storm? Rogue waves. 101 00:10:40,000 --> 00:10:49,000 Rogue waves are mysterious. Some oceanographers like to say that it's a wave that's bigger than two and a half times the average waves that are occurring. 102 00:10:50,000 --> 00:11:01,000 Also known as freak or killer waves, rogue waves have been recorded in the Great Lakes. And they can be deadly. 103 00:11:02,000 --> 00:11:16,000 Rogue waves are an extremely real thing on the Great Lakes because the water is not very deep. A lot of people are surprised by this because they would think, oh, well, you only get really big waves in the ocean. 104 00:11:17,000 --> 00:11:25,000 The thing that makes waves in a lake body, particularly a problem, is that that wave energy has nowhere to go but up. 105 00:11:26,000 --> 00:11:35,000 The Great Lakes are really like inland seas, but they have these sides. So the effects of waves and the way that waves can be produced and produced quickly is rather different. 106 00:11:36,000 --> 00:11:40,000 You can get these very, very large, very sudden waves. It's sort of like a big bathtub. 107 00:11:40,000 --> 00:11:58,000 And these waves can be changed in their shape by the surrounding topography. So that means that if it's close to the shore and there's a big wall, it can bounce off and just create a wave with different pattern and make that wave grow higher. 108 00:12:00,000 --> 00:12:05,000 Lake Superior is legendary for a strange phenomenon called the Three Sisters. 109 00:12:05,000 --> 00:12:12,000 There's an old saying with waves that waves come in threes. Oftentimes the third wave can be the biggest. 110 00:12:13,000 --> 00:12:23,000 When you have rogue waves that occur, one after another after another, the ship doesn't have a chance to recover after the first one hitting the ship, and this can cause it to sink. 111 00:12:24,000 --> 00:12:30,000 But how do we discover if rogue waves appeared on Lake Superior on that day more than 40 years ago? 112 00:12:31,000 --> 00:12:41,000 Oceanographer Dave Schwab does what nobody has ever done before. He converts the records of weather conditions into a detailed hour-by-hour model. 113 00:12:42,000 --> 00:12:52,000 We could estimate, based on the output from the meteorological model, what the wave conditions were at any point in time and any point in space during those three days. 114 00:12:53,000 --> 00:13:00,000 Schwab recreates wave heights across the lake for every hour during the ship's tragic crossing. 115 00:13:01,000 --> 00:13:21,000 We basically split the lake into a number of grid boxes. Each of those boxes that's within the lake is represented in the computer as a cell that can interact with wind from the surface and with its adjacent cells. 116 00:13:22,000 --> 00:13:29,000 Can this new mapping of the water's dynamics bring us a step closer to understanding what happened that terrible night? 117 00:13:30,000 --> 00:13:43,000 The wave model predicted that the highest waves were occurring, maybe up to 25 to 30 feet, and that was exactly the place where the Fitzgerald was and exactly the time they were there. 118 00:13:43,000 --> 00:13:53,000 And the model reveals one other crucial clue. As the waves were growing in height, the distance between them was also growing. 119 00:13:57,000 --> 00:14:04,000 Wave crests in the area of the Fitzgerald sink were becoming hundreds of feet apart. 120 00:14:04,000 --> 00:14:07,000 The same length as the SS Edmund Fitzgerald. 121 00:14:08,000 --> 00:14:18,000 So one end of the ship is on the crest of one wave, the other end of the ship is on the crest of another wave, and there's nothing in the middle to hold that ship above water. 122 00:14:19,000 --> 00:14:30,000 If this ship was so long that it was actually riding two waves at the same time, it was on each peak, then the part of the middle of the ship would just be hanging in midair and that would create a lot of stress on the whole. 123 00:14:30,000 --> 00:14:34,000 And if you have very big cargo, it could just split in half. 124 00:14:35,000 --> 00:14:54,000 The distance between wave crests becomes longer and longer. During this storm, I don't know whether that had some effect on the dynamics of the buoyancy of the ship or how it reacted to waves that long, but these are unusually long waves for the Great Lakes. 125 00:14:55,000 --> 00:15:08,000 Dave Schwab's work offers a new and very plausible explanation of the unique set of circumstances that could have caused this terrible tragedy. 126 00:15:08,000 --> 00:15:18,000 But until more evidence is uncovered, it remains a theory and our deep waters often have a way of swallowing the evidence we need. 127 00:15:25,000 --> 00:15:36,000 Where used are stories of UFOs spotted in our skies, mysterious visitors from outer space. But could there be alien craft in our oceans? 128 00:15:36,000 --> 00:15:49,000 In 2004, mysterious underwater objects are detected by US warships on a training exercise in the Pacific. It appears that no one knows what they are. 129 00:15:50,000 --> 00:15:58,000 Can newly declassified information finally reveal the secret of what's going on beneath the surface? 130 00:16:00,000 --> 00:16:07,000 November 14, Navy carrier the USS Nimitz is 100 miles off the coast of San Diego. 131 00:16:09,000 --> 00:16:14,000 Reports come in of strange unidentified objects in the water. 132 00:16:14,000 --> 00:16:21,000 Four F-A-18 hornets are sent to investigate. What they find astounds them. 133 00:16:21,000 --> 00:16:33,000 The pilots observed an object in the water roughly the size of a 747. Basically right at the surface and the water around it seemed to be boiling or churning. 134 00:16:33,000 --> 00:16:42,000 For the Navy to see an object they don't recognize is unbelievable, but that it's acting in this way is even more mysterious. 135 00:16:43,000 --> 00:16:46,000 Then the pilots spot something totally incredible. 136 00:16:47,000 --> 00:16:54,000 The pilots first observed a bigger object in the water, but then they subsequently see a smaller object about 40 foot. 137 00:16:55,000 --> 00:16:59,000 Come up to it, dock with it and then take off into the air. 138 00:16:59,000 --> 00:17:10,000 The smaller craft suddenly starts to move erratically pinballing around. The larger craft disappears into the depths, leaving no trace. 139 00:17:11,000 --> 00:17:17,000 So here we have this monster or size, whatever thing, bubbling underwater and going away. 140 00:17:18,000 --> 00:17:23,000 The smaller craft shoots off through the sky with the hornets giving chase. 141 00:17:25,000 --> 00:17:34,000 They describe it as 40 feet long and shaped like a giant tic-tac. It has no wings or visible means of propulsion. 142 00:17:34,000 --> 00:17:36,000 They're obviously tracking a mysterious object. 143 00:17:36,000 --> 00:17:43,000 And it does something else that truly defies logic. It plummets into the water at incredible speed. 144 00:17:43,000 --> 00:17:52,000 The calculations that they made of the speed that this went from about 20,000 feet to the surface of the sea was in about a second, which is completely ridiculous. 145 00:17:55,000 --> 00:18:02,000 That's obviously traveling faster than the speed of sound. Where are the shock waves? Where are the sound waves that would emanate from it? 146 00:18:03,000 --> 00:18:10,000 But then the physical impact of going from gas to the other medium liquid without having some kind of catastrophic failure. 147 00:18:11,000 --> 00:18:14,000 What we're seeing doesn't seem possible in terms of physics. 148 00:18:17,000 --> 00:18:22,000 Missile cruiser, the USS Princeton, is also taking part in the exercise. 149 00:18:22,000 --> 00:18:27,000 Her sonar picks up multiple small objects moving through the water. 150 00:18:28,000 --> 00:18:34,000 The fact that these objects are moving really, really quickly through the water, we simply don't see this. 151 00:18:34,000 --> 00:18:39,000 The fastest submarine can reach a maximum speed of 51 miles per hour. 152 00:18:39,000 --> 00:18:46,000 But these objects are reported to be traveling at 10 times that speed over 500 miles per hour. 153 00:18:46,000 --> 00:18:50,000 The science we have today can't explain it. It has me boggled. 154 00:18:51,000 --> 00:19:00,000 Evidence of this encounter remains classified until the US military finally releases it in 2017. 155 00:19:00,000 --> 00:19:06,000 What are these incredible craft that appear to defy the laws of physics? 156 00:19:06,000 --> 00:19:13,000 Is this proof of an underwater alien encounter or something else entirely? 157 00:19:21,000 --> 00:19:29,000 In 2017, the US Navy releases evidence of an encounter with unidentified submersible objects 158 00:19:29,000 --> 00:19:34,000 traveling at extraordinary speed through the Pacific Ocean. 159 00:19:34,000 --> 00:19:41,000 No known craft can travel that fast through water. So what on earth could they be? 160 00:19:42,000 --> 00:19:50,000 While we have planes that can achieve supersonic speeds through air, water is 800 times more dense. 161 00:19:50,000 --> 00:19:56,000 When objects move through an underwater environment, there's a lot more friction along the hulls of vessels. 162 00:19:56,000 --> 00:20:02,000 So they have to produce more power to be able to push through whatever they're trying to move through. 163 00:20:02,000 --> 00:20:08,000 So in water, there's more friction, more barriers to push through versus than in the air. 164 00:20:11,000 --> 00:20:17,000 The interaction between a fluid and an object's surface causes a phenomenon called skin friction drag. 165 00:20:17,000 --> 00:20:23,000 The faster you go, the more power you need at an exponentially increasing rate. 166 00:20:23,000 --> 00:20:28,000 So for something to be going down fast through water, it's got to be overcoming this friction. 167 00:20:28,000 --> 00:20:35,000 There are very real limits to how fast you can travel underwater, and these objects completely defy those limits. 168 00:20:35,000 --> 00:20:38,000 Could they have come from another world? 169 00:20:38,000 --> 00:20:42,000 The first thing that came to my mind is that this is a meteorite, and if it were a meteorite, 170 00:20:42,000 --> 00:20:48,000 you would see a burning rock and then you'd see a gigantic splash when it eventually hit the ocean. 171 00:20:48,000 --> 00:20:55,000 There's also the option of extraterrestrials, which is beyond my knowledge and beyond anyone's if they're extraterrestrial. 172 00:20:55,000 --> 00:21:02,000 But there is one scientific theory that might explain how an object could move through water at great speed 173 00:21:02,000 --> 00:21:08,000 without the involvement of extraterrestrial beings. It's a technology called supercavitation. 174 00:21:08,000 --> 00:21:11,000 This is where something is working in an air bubble. 175 00:21:11,000 --> 00:21:17,000 So instead of it having friction of water to deal with, it's got the friction of moving through an air bubble, 176 00:21:17,000 --> 00:21:22,000 and the air around it is what's interacting with the water, so it's friction of air and water, 177 00:21:22,000 --> 00:21:26,000 which of course is very, very small, so it manages to go that much faster. 178 00:21:26,000 --> 00:21:32,000 Over 20 years ago, Russian scientists developed a supercavitating torpedo, 179 00:21:32,000 --> 00:21:36,000 said to travel six times faster than its predecessors. 180 00:21:36,000 --> 00:21:42,000 The Russian Sval torpedo is alleged to use supercavitation to achieve unmatched high speeds, 181 00:21:42,000 --> 00:21:45,000 but it's never been used in combat, so we're not really sure. 182 00:21:45,000 --> 00:21:53,000 New evidence is emerging which suggests the Russians may not be the only ones working on underwater supercavitation technology. 183 00:21:53,000 --> 00:21:58,000 Recently, the US Navy have filed for several mysterious patents. 184 00:21:58,000 --> 00:22:04,000 Three of these patents are suggestive of a high speed, aerospace, underwater craft 185 00:22:04,000 --> 00:22:07,000 that could potentially be capable of these kinds of speeds. 186 00:22:07,000 --> 00:22:11,000 The other question is, is this patent really a patent of something that already exists, 187 00:22:11,000 --> 00:22:18,000 or is this a patent where this is the direction that they're thinking in terms of developing future technology? 188 00:22:19,000 --> 00:22:23,000 Is it something Americans were developing and they're not admitting that they had? 189 00:22:23,000 --> 00:22:26,000 Is it something someone else was developing? 190 00:22:26,000 --> 00:22:29,000 We don't know, so that's what the mystery is. 191 00:22:29,000 --> 00:22:32,000 The Nimitz sighting happens in 2004. 192 00:22:32,000 --> 00:22:39,000 The patents aren't lodged until more than a decade later, but could they somehow be linked? 193 00:22:39,000 --> 00:22:42,000 Supercavitation has never been seen, it's never really been demonstrated, 194 00:22:42,000 --> 00:22:46,000 it's never been proven, it is entirely a theory which we're working towards. 195 00:22:46,000 --> 00:22:53,000 So if it was something man-made, then it is technology which has yet to be admitted to the world. 196 00:22:54,000 --> 00:23:02,000 But if this really is top secret technology, why would the US military release the footage and publish the patents? 197 00:23:02,000 --> 00:23:07,000 These sightings are so unusual and they defy physics in so many ways, 198 00:23:07,000 --> 00:23:10,000 and the fact that we know about it, I think is highly unusual as well. 199 00:23:11,000 --> 00:23:16,000 There is one possibility which could explain the sudden release of this information. 200 00:23:16,000 --> 00:23:22,000 It could also be the US Navy putting a ruse out there to wind up and make the Chinese and the Russians 201 00:23:22,000 --> 00:23:25,000 and everyone else spend a lot of money on something which is impossible. 202 00:23:25,000 --> 00:23:28,000 Could this have been a function of war games? 203 00:23:28,000 --> 00:23:32,000 Could one side have been toying with the other with some new technology? 204 00:23:32,000 --> 00:23:34,000 That potential exists. 205 00:23:35,000 --> 00:23:40,000 So are these extraordinary sightings a glimpse into our technological future? 206 00:23:40,000 --> 00:23:43,000 Or evidence of extraterrestrial life? 207 00:23:43,000 --> 00:23:46,000 Or an exercise in military deception? 208 00:23:46,000 --> 00:23:49,000 The jury is still out. 209 00:23:57,000 --> 00:24:03,000 The ocean floor is littered with shipwrecks, possibly as many as three million of them. 210 00:24:03,000 --> 00:24:07,000 Many were sunk in battle or wrecked by rocks. 211 00:24:07,000 --> 00:24:14,000 And there are some ships still intact on the seabed that date back over 2,000 years. 212 00:24:14,000 --> 00:24:20,000 So how could one disappear from the bottom of the ocean overnight? 213 00:24:20,000 --> 00:24:24,000 Shipwrecks can't just disappear. What can they? 214 00:24:34,000 --> 00:24:41,000 I've witnessed up close the sheer size and bulk of some sunken vessels. 215 00:24:41,000 --> 00:24:48,000 And for a huge shipwreck to suddenly vanish from the seabed seems impossible. 216 00:24:48,000 --> 00:24:50,000 But is it? 217 00:24:50,000 --> 00:24:58,000 Off the coast of Borneo are the wrecks of three Japanese cargo ships, which sank over 70 years ago. 218 00:24:58,000 --> 00:25:04,000 Known as the Yusokan wrecks, they become rich artificial reefs. 219 00:25:04,000 --> 00:25:10,000 On January 31st, 2017, a team of divers goes to see the wrecks. 220 00:25:10,000 --> 00:25:13,000 But they've completely disappeared. 221 00:25:13,000 --> 00:25:17,000 These are documented wrecks that have just gone missing. 222 00:25:17,000 --> 00:25:22,000 People go back to look for these wrecks. They're gone. There's a giant hole in the seabed. 223 00:25:22,000 --> 00:25:30,000 Where these huge hulks once lay, nothing but an eerie void and a few mangled scraps of metal remain. 224 00:25:30,000 --> 00:25:44,000 You would expect pieces of it to be left behind, but to go to a known shipwreck and to just see a depression in the sediment there and virtually nothing left behind, that is bizarre. 225 00:25:45,000 --> 00:25:51,000 Many wrecks do slowly dissolve over time due to saltwater corrosion. 226 00:25:51,000 --> 00:25:59,000 But the Yusokan wrecks disappeared much more suddenly. How is that possible? 227 00:25:59,000 --> 00:26:03,000 There are a number of theories about what might have happened. 228 00:26:03,000 --> 00:26:08,000 One of the possible reasons that's been proposed is that maybe it has to do with commercial fishing. 229 00:26:09,000 --> 00:26:15,000 For years, shipwrecks have been disturbed by commercial fishing practices. 230 00:26:15,000 --> 00:26:22,000 Could the vast net of a deep sea trawler have caught on one of the wrecks and dragged it across the seabed? 231 00:26:22,000 --> 00:26:29,000 There's no fishing boat out there that's going to trawl and move a huge battleship on the ocean floor. 232 00:26:29,000 --> 00:26:35,000 Our deep oceans also have strong currents running far beneath the surface. 233 00:26:36,000 --> 00:26:43,000 Cold temperatures and high concentrations of salt make them much denser than the surrounding water. 234 00:26:43,000 --> 00:26:51,000 We do know some currents can carve deep forges through the ocean, can give really deep trenches. 235 00:26:51,000 --> 00:26:56,000 Ocean currents have been known to move aircraft debris large distances. 236 00:26:56,000 --> 00:27:01,000 But we're talking about three huge shipwrecks weighing thousands of tons. 237 00:27:01,000 --> 00:27:06,000 There is another force that lies beneath our ocean bed that could be powerful enough. 238 00:27:06,000 --> 00:27:13,000 The ocean floor is very active geologically. You only have to look at footage of the deep ocean to know there are very strange things happening down there. 239 00:27:13,000 --> 00:27:17,000 For example, vents giving off tall columns of gases. 240 00:27:17,000 --> 00:27:22,000 There are underwater earthquakes and volcanoes. We're just not normally aware of them. 241 00:27:22,000 --> 00:27:27,000 We do have equipment which monitors seismic activity underwater around the world. 242 00:27:27,000 --> 00:27:32,000 But our data doesn't show any activity which correlates to where the ships are disappearing. 243 00:27:32,000 --> 00:27:40,000 A deep sea tremor of the magnitude necessary to swallow these ships would surely have been picked up by seismic monitoring. 244 00:27:40,000 --> 00:27:44,000 And new evidence has come to light that deepens the mystery. 245 00:27:44,000 --> 00:27:50,000 The Yusrkhan wrecks are not the only shipwrecks to have gone missing in recent years. 246 00:27:50,000 --> 00:27:54,000 This has become a widespread phenomenon. 247 00:27:54,000 --> 00:28:01,000 There's this really unusual situation happening right now where worldwide shipwrecks are seemingly disappearing. 248 00:28:01,000 --> 00:28:06,000 Ships like HMS Warrior in Danish waters. 249 00:28:06,000 --> 00:28:12,000 The HMS were pulse and HMS Prince of Wales that were sunk in Malaysia. 250 00:28:12,000 --> 00:28:16,000 And the question is what's going on here? 251 00:28:25,000 --> 00:28:32,000 Divers revisiting the site of three sunken Japanese cargo ships discover they vanished. 252 00:28:32,000 --> 00:28:36,000 And other shipwrecks across the world are going missing. 253 00:28:36,000 --> 00:28:39,000 So what's going on? 254 00:28:39,000 --> 00:28:48,000 The fact that it's happening all over the world in multiple locations and in the numbers that we're seeing, it's a catastrophe. 255 00:28:49,000 --> 00:28:54,000 Perhaps there's a clue in the type of ships that are disappearing. 256 00:28:54,000 --> 00:28:59,000 They have one thing in common. They were all sunk in World War II. 257 00:28:59,000 --> 00:29:04,000 And fragments left at some of the sites give us further clues. 258 00:29:04,000 --> 00:29:13,000 It appears that these wrecks have been taken by human hands in search of one particular commodity. 259 00:29:13,000 --> 00:29:19,000 One of the reasons that they're disappearing is because of the valuable metals that are in these shipwrecks. 260 00:29:19,000 --> 00:29:26,000 A shipwreck represents a literal treasure trove of metals. Brass, copper. 261 00:29:26,000 --> 00:29:31,000 There is tons and tons and tons of metals in these things. 262 00:29:31,000 --> 00:29:37,000 Under international law, these shipwrecks remain the property of the country they came from. 263 00:29:37,000 --> 00:29:43,000 In the case of the Yusukan wrecks, the government had permitted a company to do archaeological research. 264 00:29:43,000 --> 00:29:48,000 But someone went a step further and removed the wrecks entirely. 265 00:29:48,000 --> 00:29:53,000 This is an example of what's referred to as metal piracy. 266 00:29:53,000 --> 00:29:59,000 These are people who are illegally salvaging these shipwrecks. 267 00:29:59,000 --> 00:30:05,000 Taking the metal, selling them, I would presume in the black market. 268 00:30:05,000 --> 00:30:15,000 Who are these metal pirates? We don't know what nations they normally come from, what their underground network is like. 269 00:30:15,000 --> 00:30:21,000 Many of these shipwrecks contain something that makes them especially valuable. 270 00:30:21,000 --> 00:30:27,000 World War II ships are one of the few remaining sources of a particularly rare category of metal. 271 00:30:27,000 --> 00:30:34,000 This metal is highly valuable because for most of it it was produced before the Second World War. 272 00:30:34,000 --> 00:30:39,000 So it has what's referred to as the pre-nuclear signature. 273 00:30:39,000 --> 00:30:44,000 We're talking about metal that was produced prior to nuclear testing. 274 00:30:44,000 --> 00:30:53,000 Decades beneath the watery depths have protected the ships from radiation, which metal above the surface has been exposed to. 275 00:30:53,000 --> 00:31:02,000 They're called low-grade metals, which means that they have a lower radiation value, and they're very useful for medical use, for technological use. 276 00:31:02,000 --> 00:31:11,000 And it's also highly used in modern scientific equipment. So there's a big demand for this kind of metal. 277 00:31:11,000 --> 00:31:21,000 Metals with little or no trace of radiation are able to produce more accurate readings for finely tuned instruments, from Geiger counters to space sensors. 278 00:31:21,000 --> 00:31:30,000 So they command a very high price. But the idea that these historic sites are being picked apart is for many people, abhorrent. 279 00:31:30,000 --> 00:31:34,000 There are World War II wrecks with World War II dead on them. 280 00:31:34,000 --> 00:31:40,000 War vessels with war dead on them should be considered war graves and sacred. 281 00:31:40,000 --> 00:31:48,000 We're talking about places where people died. We're talking about military battles. And they're essentially a place that needs to be honored and respected. 282 00:31:48,000 --> 00:31:56,000 Can anything be done to stop the illegal salvage before all these irreplaceable monuments are stolen? 283 00:31:56,000 --> 00:32:03,000 These are well-organized professionals. They have to have the right equipment. It's not cheap. They're going out there. They're using commercial diving. 284 00:32:03,000 --> 00:32:14,000 It's hard to police something that's underwater in vast areas of ocean. But new satellite technology could help the authorities catch the pirates in the act. 285 00:32:14,000 --> 00:32:20,000 With all the satellites that we have today, if it's clear enough water and shallow enough, you can even see the shipwrecks themselves from space. 286 00:32:20,000 --> 00:32:27,000 They can actually monitor subtle changes that are happening on the surface where these shipwrecks sites are and be able to recognize if something is happening. 287 00:32:27,000 --> 00:32:36,000 When you try to move something as large as a shipwreck from the sea floor, you're undoubtedly going to leave a large sediment plume. 288 00:32:36,000 --> 00:32:44,000 And Landsat can also be used to detect these sediment plumes to give some indication of where wrecks are under threat. 289 00:32:44,000 --> 00:32:52,000 These plumes would show in discoloration or differences in water, and they could give us an idea that the water has been disturbed. 290 00:32:52,000 --> 00:33:00,000 Satellites could prove vital in helping us to monitor these wrecks and to act quickly if we spot anything suspicious. 291 00:33:00,000 --> 00:33:05,000 Technology is really our way to protect these wrecks. 292 00:33:05,000 --> 00:33:13,000 It's important to remember that these are cultural heritage artifacts that need to be preserved for everyone. 293 00:33:13,000 --> 00:33:23,000 Will these technological spies in the sky be enough to turn the tide on the mysterious metal pirates before it's too late? 294 00:33:29,000 --> 00:33:39,000 I've been lucky enough to explore some amazing underwater sites, and among the most jaw-dropping I've visited are blue holes. 295 00:33:40,000 --> 00:33:46,000 Diving these deep marine sinkholes is like venturing into an abyss. 296 00:33:46,000 --> 00:33:54,000 But what has led to one particular blue hole being dubbed the most deadly dive site in the world? 297 00:33:55,000 --> 00:34:05,000 30 miles east of Mount Sinai on the coast of the Egyptian Red Sea lies a remarkable underwater formation known as the Blue Hole of Dahab. 298 00:34:06,000 --> 00:34:10,000 The Blue Hole in Dahab, Egypt is this really, really special place. 299 00:34:10,000 --> 00:34:18,000 Dahab's Blue Hole is a giant circular sinkhole, a deep vertical shaft surrounded by coral and rock. 300 00:34:18,000 --> 00:34:24,000 Its pristine waters and proximity to the shore have lured divers to it for decades. 301 00:34:27,000 --> 00:34:32,000 But despite its beauty, this place holds a deadly mystery. 302 00:34:32,000 --> 00:34:39,000 The Blue Hole off the Red Sea in Egypt is one of the world's most mesmerizing underwater phenomena. 303 00:34:39,000 --> 00:34:42,000 The trouble is it's also a deft trap. 304 00:34:46,000 --> 00:34:56,000 In August 2004, seasoned diver Andrei Nikitin embarks on his first Dahab Blue Hole dive with his buddy and their guide. 305 00:34:56,000 --> 00:35:03,000 Knowing the challenges of the site, he has the right gear and has even completed several preparatory dives. 306 00:35:03,000 --> 00:35:07,000 Despite all this, he never makes it out alive. 307 00:35:10,000 --> 00:35:16,000 This is an experienced diver. He's well prepared. He's organised. It doesn't make sense. 308 00:35:16,000 --> 00:35:19,000 This isn't an isolated incident. 309 00:35:19,000 --> 00:35:28,000 The Dahab Blue Hole is estimated to have claimed the lives of around 200 divers, making it the world's deadliest dive site. 310 00:35:28,000 --> 00:35:33,000 200 fatalities for a single dive site is very, very high. 311 00:35:33,000 --> 00:35:38,000 This makes the Blue Hole only second to Everest in terms of the dangers. 312 00:35:38,000 --> 00:35:44,000 It's very alarming for one spot, for one popular diving spot. 313 00:35:45,000 --> 00:35:52,000 Is there something lurking at the bottom of this underwater chasm that's luring divers down to their deaths? 314 00:35:52,000 --> 00:36:02,000 Despite its beauty, the Blue Hole is a place that the local Bedouin tribes have long avoided, because according to legend, it's cursed. 315 00:36:02,000 --> 00:36:10,000 There's a Bedouin legend of a young girl who drowned while trying to escape and arranged marriage and her spirit now haunted. 316 00:36:10,000 --> 00:36:15,000 This story indicates something very strange has been going on there for some time. 317 00:36:15,000 --> 00:36:20,000 The curse of a Bedouin bride? Or is there something more tangible at work here? 318 00:36:20,000 --> 00:36:41,000 Dahab's Blue Hole is the world's most dangerous dive site. The Bedouin believe it may be cursed by the ghost of a local girl who drowned there. 319 00:36:41,000 --> 00:36:47,000 What is lurking in its depths that has claimed the lives of so many divers? 320 00:36:48,000 --> 00:36:53,000 There are many unseen forces in our oceans that can kill. 321 00:36:53,000 --> 00:37:03,000 The Red Sea is home to more than 40 types of shark, including the Tiger Shark, one of the few species known to bite humans. 322 00:37:03,000 --> 00:37:11,000 It also has deep water currents, capable of pulling a diver down into the depths. 323 00:37:12,000 --> 00:37:19,000 But from the evidence so far, it doesn't seem either of these factors are responsible for the deaths at Dahab. 324 00:37:21,000 --> 00:37:28,000 Could a new insight help us to understand what makes this beautiful Blue Hole such a killer? 325 00:37:30,000 --> 00:37:37,000 It's a deep dive. You want to have training and experience, and it's a dive that you want to have your wits about you. 326 00:37:37,000 --> 00:37:46,000 Its deepest depth is about 400 feet. The maximum depth for recreational divers is 130 feet. 327 00:37:50,000 --> 00:37:56,000 Diving deep can come with a dangerous side effect, something known as nitrogen narcosis. 328 00:37:58,000 --> 00:38:06,000 Narcosis is having a high amount of nitrogen that accumulates in your body, and that changes your perception of what's around you. 329 00:38:06,000 --> 00:38:09,000 So it's very similar to being drunk. 330 00:38:10,000 --> 00:38:15,000 Lightheadedness, a little dizzy, you're confused. 331 00:38:17,000 --> 00:38:21,000 They say it's the effect of drinking a couple martinis on an empty stomach. 332 00:38:22,000 --> 00:38:31,000 It can have a euphoric effect on the diver. They can be afraid all of a sudden. They can lose their orientation. 333 00:38:32,000 --> 00:38:36,000 This is not something that you want to happen to you when you're at depth. 334 00:38:38,000 --> 00:38:46,000 It doesn't matter how experienced you are, this will impact your judgment, it will impact your decision making, and it changes how you respond to things. 335 00:38:47,000 --> 00:38:49,000 This can be totally lethal. 336 00:38:51,000 --> 00:38:56,000 And there's another spectacular feature of the Dahab Blue Hole that could be involved. 337 00:38:57,000 --> 00:39:04,000 Archaeologist Beverly Goodman experienced it firsthand when she dived the Dahab Blue Hole in 1997. 338 00:39:05,000 --> 00:39:14,000 You're coming down the side of the coral wall. You have this beautiful coral all around the ring, and then you're going down in depth and below you it just goes into the blue and it gets darker and darker. 339 00:39:15,000 --> 00:39:18,000 But then this light starts coming through this large arch. 340 00:39:18,000 --> 00:39:29,000 The arch is a strange feature unique to the Dahab Blue Hole. At a depth of approximately 170 feet, it's a mysterious tunnel that connects the main shaft to the open sea. 341 00:39:30,000 --> 00:39:36,000 Suddenly you find yourself into this cavern which link the sinkhole with the Red Sea. 342 00:39:37,000 --> 00:39:43,000 Light reflective through the arch creates a mesmerizing but incredibly disorientating effect. 343 00:39:44,000 --> 00:39:46,000 The arch is this incredible optical illusion. 344 00:39:46,000 --> 00:39:55,000 It is this beautiful passageway that can appear both small and large depending on your position thanks to the fraction of the light going through it. 345 00:39:56,000 --> 00:39:59,000 And then it opens up to this clear water going to 1,000 meters. 346 00:40:00,000 --> 00:40:04,000 It's a huge temptation for divers to follow this passageway out to the open sea. 347 00:40:05,000 --> 00:40:12,000 The dazzling underwater illusions can make it look like an easy 30 foot swim. In fact, it's over 80. 348 00:40:12,000 --> 00:40:18,000 Judging distance underwater is quite tricky, especially when it's clear water. You really lose perception. 349 00:40:19,000 --> 00:40:26,000 So what you think is close might not be as close as you think. What you think is far might not be as far as you think. 350 00:40:27,000 --> 00:40:33,000 Could a deadly cocktail of Narcosis confusion and optical illusion be behind these divers' deaths? 351 00:40:34,000 --> 00:40:38,000 You're feeling really good. You're feeling, oh this is basically laughing gas at this point. 352 00:40:38,000 --> 00:40:42,000 So you're feeling a little bit high. You're seeing this beautiful light coming through. 353 00:40:43,000 --> 00:40:52,000 You're not exactly where you're supposed to be, but the draw of going towards that light and going through it is really irresistible. 354 00:40:53,000 --> 00:40:57,000 Being a confused diver at depth could be fatal. 355 00:40:58,000 --> 00:41:04,000 Is the Bedouin's ghostly girl in fact the fatal attraction of this beautiful but deadly place? 356 00:41:05,000 --> 00:41:11,000 Humans love to push the limits and I don't know if it's humans are attracted to these dangerous experiences, 357 00:41:12,000 --> 00:41:17,000 but I think we really enjoy the spectacularness of the unknown. 358 00:41:22,000 --> 00:41:27,000 We still have so much to learn about the spectacular underwater realm, 359 00:41:28,000 --> 00:41:33,000 but the deadly Dahab Blue Hole teaches us a valuable lesson. 360 00:41:34,000 --> 00:41:42,000 The world beneath the waves is a different dimension where the normal rules don't apply and we forget that at our peril.