The Cayman Trough, (also known as the Cayman Trench, Bartlett Deep and Bartlett Trough) is a complex transform fault zone pull apart basin which contains a small spreading ridge on the floor of the western Caribbean Sea between Jamaica and the Cayman Islands. It is the deepest point in the Caribbean Sea and forms part of the tectonic boundary between the North American Plate and the Caribbean Plate. It extends from the Windward Passage, going south of the Sierra Maestra of Cuba toward Guatemala. The transform continues onshore as the Motagua Fault, which cuts across Guatemala and extends offshore under the Pacific Ocean, where it intersects the Middle America Trench subduction zone.
It was site of the fictional movie The Abyss.