Andrew (Andy) wrote
                                    "It's thought that if a giant gas
release (and they have been
documented in geophysical records) reached the surface directly under a
boat, the boat would sink instantly, no longer being supported by the
water. There would be no time for a radio message unless the operator were
already on the set, and he probably wouldn't know what was happening."
 
there was also some speculation that the disappearances in the so called
"Bermuda Triangle" are due in part to massive releases of methane gas
trapped beneath the layers of offshore sediments. Like Andrew stated if a
ship where to be over this release the ship would sink so fast as dropping
it off a cliff. The disappearances of aircraft could be caused by flying
into this released cloud would spark an explosion that nothing could
survive.
In 1982 British Petroleum lost a oil platform when it drilled into a gas
pocket, the result is known as a blow-out and the whole platform sank into
800n ft of the chilly North Sea.
Some research has been conducted on tapping into these huge pockets of
frozen methane but to date we lack the technology to make this feasible.