In December 1945, five Navy aircraft disappeared off the Florida coast, and so did the search plane sent after them. In March 1918, the Navy cargo ship Cyclops vanished en route to Baltimore with 309 crewmen aboard. These are just two of the mysterious disappearances that have made the Bermuda Triangle so notorious. An estimated 300 vessels have sunk in the nearly 500,000-square-mile expanse of the Atlantic Ocean between Florida, Bermuda and Puerto Rico — giving rise to supernatural explanations that blame everything from aliens to the lost continent of Atlantis.

So what’s really behind these unexplained mysteries? The National Geographic Channel special "Drain the Bermuda Triangle," premiering Dec.7, provides some practical explanations, using computer simulations based on sonar mapping of the ocean floor to reveal the hidden landscape below the waves.

"It was important to include and convey the fact that although the Bermuda Triangle is a concept that is firmly lodged in the public's imagination as a place of mystery, most of the area's disappearances can be ascribed to natural phenomena or human error," says program producer Crispin Sadler, who previously produced "Drain the Great Lakes" for Nat Geo. "Because our representation of the seabed is based purely on data, we can show only what has been found, but in doing so we can also show why it has been so difficult to find anything once it disappeared beneath the waves. The statistics for the Triangle area are eye-opening: on average nearly three miles deep with some parts dropping down to five miles, some of the deepest ocean anywhere on the planet. The islands on the fringes of the Triangle are sitting on the tops of mountains and plateaus many thousands of feet high, which if found on land would dwarf even the likes the Grand Canyon."

While the production filmed in the Triangle area last summer, British CGI facility 422 South worked on the spectacular recreations of the sea bottom, based on scientific data.

The wreck of the SS Sapona

The wreck of the SS Sapona, which ran aground off Bimini during a 1926 hurricane. (Photo: Crispin Sadler/Mallinson Sadler Productions)

"Measuring depth and the contours of the seabed used to be done with a line weighted by a lead weight. Many areas of the seabed were mapped in this incredibly slow and laborious manner," says Sadler. "Nowadays, technology based on the World War II sonar developed to track enemy submarines is used. This relies on the fact that sound waves penetrate water far more effectively than light. These sound waves will be reflected back off a solid surface and will eventually give an accurate picture of the size and shape of an object, even at depth. Multiply this many thousands of times and a picture of the seabed can be built up. What used to take years now takes days. The images that are produced are used by scientists, hydrographers and mariners but can remain somewhat mystifying to the general public. What we do is take the data and convert them into photo-realistic images."

These include such geographical features as mountains, canyons, even an underwater desert. "The depths and topography of the deepest part of the Atlantic Ocean — the Puerto Rico Trench — has one of the most awesome landscapes (once drained) anywhere on the planet," observes Sadler. "We were very fortunate that the high-resolution data were released by the U.S. Geological Survey in September, just in time for us to incorporate it into the film." He adds that phenomena like the Blue Holes in the Bahamas "were another complete revelation, so deep and so vast as to defy comprehension. We could portray these in a way never seen before."

Sadler believes that the Bermuda Triangle legends persist because "the idea that ships, planes and people can go missing seemingly without explanation, never to be seen again, feeds into a mindset that just wants answers, however irrational." But as the special points out, weather and geography are the more likely culprits.

"Climatic conditions there can change rapidly from incredibly calm and benign to stormy and dangerous in a matter of minutes," Sadler says. "The Triangle area does see more than its fair share of turbulent weather, what with systems coming down from the north combining with hurricanes breeding in the Gulf of Mexico, Caribbean and warmer waters of the western Atlantic and the effects of the powerful Gulf Stream. But even on an average day, storms can spring up out of nowhere and unless there are good ship-to-shore communications. Once out of sight of land, most VHF radios and cell phones do not work), vessels can just disappear without warning.

"On the seabed there are substances that potentially have the power to sink ships and even low-flying planes," he continues. "In such a seismically active area, especially in the southern part of the Triangle, tsunamis can wreak terrible damage on or close to the shore."

Philippe Rouja looking at the paddle wheel of the wreck of the Mary Celestia

Philippe Rouja looking at the paddle wheel of the wreck of the Mary Celestia. (Photo: Dan Stevenson/Mallinson Sadler Productions)

He has some practical advice for anyone venturing into the Triangle. "If you own a small boat or plane, make sure you are prepared for bad weather, that your navigation systems, GPS, etc. are fully functioning and in case they fail, know how to read a map and follow a compass bearing. Given how accessible and cheap satellite phones are, take one of them. Finally, if you do go out of sight of land, inform the authorities or even family or friends on shore, giving them your approximate travel plans and schedule. It is incredibly difficult to find anything out in the ocean so you must give the Coast Guard every opportunity to increase their chances of finding you in the event of an incident."

Sadler believes "Drain the Bermuda Triangle" will give viewers a new perspective and understanding of the area and what has occurred there. "When people realize how vast an area the Triangle is and how deep it is, they will understand better why ships and planes go missing in the first place and why it is so difficult to find any trace of any wreckage," he says. "The Malaysian Airlines flight has shown how even the largest aircraft can disappear off the face of the earth, so it's not surprising that smaller vessels and planes can disappear as well. Until actual evidence is found, the more fanciful explanations will still exist, although we would like to think that some of these can now be debunked. Many of the Triangle's mysteries can be put down to nature," he sums up. "Nature is the force to be reckoned with, not the supernatural."

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Missing planes, sunken ships and unexplained mysteries
National Geographic's "Drain the Bermuda Triangle" provides some practical explanations for the ocean's most mysterious region.