This has been mentioned a couple of times however something I watched on the television a few weeks ago explained the answer.
Simply the program was discussing magnetics, and in it they showed an old fashioned byplane (propellor mounted on the nose) and explained that a magnetic had to be mounted in the plane near the compass to "Justify" the magnetic poles.
They showed that when the plane was turned off the compass pointed north, however when the plane was turned on and the electrics was live it interferred with the compass causing it to go haywire.
It can be suggested that the Bermuda triangle is a well transversed shipping trade route from the Caribbean. At the time of the Bermuda triangle hysteria it was circa 1930's when the Electronics equipment was first being added to ships and planes. So it could be suggested the loss of ships and planes was down to this and to the speed at which the weather can change in that region of the world.