section of the North Atlantic Ocean off North America in which more than 50 ships and 20 airplanes are said to have mysteriously disappeared. The area, whose boundaries are not universally agreed upon, has a vaguely triangular shape marked by the southern U.S. coast, Bermuda, and the Greater Antilles.

Reports of unexplained occurrences in the region date to the mid-19th century. Some ships were discovered completely abandoned for no apparent reason; others transmitted no distress signals and were never seen or heard from again. Aircraft have been reported and then vanished, and rescue missions are said to have vanished when flying in the area. However, wreckage has not been found, and some of the theories advanced to explain the repeated mysteries have been fanciful. Although theories of supernatural causes for these disappearances abound, geophysical and environmental factors are most likely responsible. One hypothesis is that pilots failed to account for the agonic line—the place at which there is no need to compensate for magnetic compass variation—as they approached the Bermuda Triangle, resulting in significant navigational error and catastrophe. Boaters and fliers continue to venture through the triangle without event.