An explanation for some of the disappearances focuses on the presence of vast fields of methane hydrates on the continental shelves. A paper was published in 1981 by the United States Geological Survey about the appearance of hydrates in the Blake Ridge area, off the southeastern United States coast. Periodic methane eruptions may produce regions of frothy water that are no longer capable of providing adequate buoyancy for ships. If this were the case, such an area forming around a ship could cause it to sink very rapidly and without warning. Laboratory experiments have proven that bubbles can, indeed, sink a scale model ship by decreasing the density of the water.

Hypothetically, methane gas might also be involved in airplane crashes, as it is not as dense as normal air and thus would not generate the amount of lift required to keep the airplane flying. Methane can cut out an aircraft engine with very little levels of it in the atmosphere.

Research has shown that tidal, freak, or rogue waves can reach up to 30 m (100 feet) in height and are capable of sinking large ships within moments. Although these are very rare, in some areas ocean currents mean they happen more often than the normal. Such waves have now been hypothesized as a cause for many unexplained shipping losses over the years.

Some research suggests that some of these waves are caused by giant bubbles of methane rising to the surface. These giant bubbles are created when methane vents at the ocean bottom become clogged; then pressure builds up and eventually the gas bursts out and rises rapidly to the surface thus generating the wave. Research has shown that such bubbles are able to sink scale sized ships with great ease and speed.

Flight 19

One of the known Bermuda Triangle incidents concerns the loss of Flight 19, a squadron of five U.S. Navy TBM Avenger torpedo bombers on a training flight out of Fort Lauderdale, Florida, on December 5, 1945. According to Berlitz, the flight consisted of expert Marine Corps aviators who, after reporting a number of odd visual effects, simply disappeared, an account which isn't entirely true. Furthermore, Berlitz claims that because the TBM Avenger bombers were built to float for long periods, they should have been found the next day considering what were reported as calm seas and a clear sky. However, not only were they never found, a Navy search and rescue seaplane that went after them was also lost. Adding to the intrigue is that the Navy's report of the accident was ascribed to "causes or reasons unknown".

While the basic facts of Berlitz's version of the story are essentially accurate, some important details are missing. The image of a squadron of seasoned combat aviators disappearing on a sunny afternoon is inaccurate. Rather, it was a squadron of lost, inexperienced flight trainees forced to ditch their out-of-fuel airplanes into unknown stormy waters in the dark of night. As for the Navy's report, it is claimed that the original report blamed the accident on the commander's confusion (Lt. Taylor abandoned his airplanes twice in the Pacific after getting lost returning to his carrier), but the wording was changed in deference to the wishes of his family.

Another factor to consider is that the TBM Avenger Aircraft were never designed for crash-landing into water. Wartime experinece in the Pacific showed that an Avenger aircraft would sink very quickly if landed on the water. Especially with novice pilots at the helm - an Avenger would be very difficult to land on calm water - let alone the perilous rough seas in the Bermuda Triangle.

If the disappearance of Flight 19 had been an isolated incident, it would have remained one of the great mysteries of modern aviation. However, aircraft disappearances continued to be reported near the same location, some accompanied by equally extended and confusing radio traffic, including that of a four-engine Tudor IV airliner named Star Tiger, in the predawn hours of January 31, 1948.

Piloted by Captain B. W. McMillan, the airliner, which carried twenty-nine passengers and crew on board, had left hours earlier from Santa Maria, Azores, one of numerous scheduled fuel stopover points on its route from London, England to Havana, Cuba. While approaching Bermuda, McMillan made the expected contact with Kindley Field, the next stopover, requesting a radio bearing to calibrate his navigation systems and ensure he remained on course. With the response indicating that the plane was slightly off course, its position was corrected after Bermuda relayed a first-class bearing of 72 degrees from the island. At this point, with Star Tiger less than two hours flight away, McMillan gave confirmation of an ETA of 05:00 hours, an hour late due to strong headwinds; no further transmission from the aircraft was ever received.

Armed with precise reports of the plane's last known position, rescue operations were launched after the craft was determined overdue for arrival; but no trace of the aircraft was ever found.

In the report issued soon thereafter by the Civil Air Ministry, numerous hypotheses as to what might have occurred during the flight's final two hours are given, before each being subsequently rejected: "There would accordingly be no grounds for supposing that Star Tiger fell into the sea in consequence of having been deprived of her radio, having failed to find her destination, and having exhausted her fuel." "There is good reason to suppose that no distress message was transmitted from the aircraft, for there were many radio receiving stations listening on the aircraft's frequencies, and none reported such a message." "...The weather was stable, there were no atmospheric disturbances of a serious kind which might cause structural damage to the aircraft, and there were no electrical storms." It was ruled that the aircraft could not have gone off course, as the broadcast bearing from Bermuda, with winds pervailing, would have brought it within thirty miles of the island: "The aircraft could hardly have failed to find the island in a short time, in the conditions of visibility which prevailed." Engine difficulty was ruled out as a likely cause, since at such late stage in the flight, without the added weight of extra fuel aboard, the aircraft might have been flown safely on three, or even two, engines instead of the four it had. The probability of the aircraft entirely losing three engines in the course of under two hours was considered absurd.

Faced with the accumulation of evidence, or perhaps lack thereof, the board of investigation addressed the loss of the Star Tiger with remarked eloquence: "In closing this report it may truly be said that no more baffling problem has ever been presented for investigation. In the complete absence of any reliable evidence as to either the nature or the cause of the accident of Star Tiger the Court has not been able to do more than suggest possibilities, none of which reaches the level even of probability. Into all activities which involve the co-operation of man and machine two elements enter of a very diverse chaarcter [sic?]. There is an incalculable element of the human equation dependent upon imperfectly known factors; and there is the mechanical element subject to quite different laws. A breakdown may occur in either separately or in both in conjunction. Or some external cause may overwhelm both man and machine. What happened in this case will never be known and the fate of Star Tiger must remain an unsolved mystery."