Below

Below (2002) is a supernatural submarine thriller from David Twohy that you can watch online on iFILM. Deep in the wartime Atlantic, the American sub USS Tiger Shark picks up three survivors from a sunken British hospital ship, and almost immediately the vessel stops behaving like a machine should.

One of the rescued is a woman, Claire, played by Olivia Williams, and old Navy superstition says a woman aboard brings disaster. The radio starts catching voices that aren't there, lights flicker in the bulkheads, and the crew hears sounds the hull can't explain. Command falls to the jittery Lt. Brice, played by Bruce Greenwood, who is hiding what really happened to the boat's previous captain. The deeper they dive to dodge a German destroyer, the heavier the pressure becomes, and not just from the water.

Twohy, who would go on to the Riddick films, locks you inside a steel tube and works the claustrophobia hard, leaning on groaning metal and dead silence instead of cheap jump scares. The cast includes Matthew Davis, Holt McCallany and a very young Zach Galifianakis. If you like haunted-sub horror where the ghost might be one of the crew, this is an underrated find. Stream Below (2002) online on iFILM.