US Navy
Naval Historical Center: Exorcizing the Devil's Triangle
Howard L. Rosenberg writes this article about the area known as "The Devil's Triangle" or "The Bermuda Triangle." Besides discussing famous lost ships and airplanes, Rosenberg gives detailed information about the geography of the sea...
Wikimedia
Wikipedia: Oceanic Trench
Wikipedia provides brief information on oceanic trenches, and has a hyperlinked list of major world trenches.