One of Hitchcock's lesser-known movies, but one of my favorites. The plot is straightforward: a socialite, a wealthy businessman, a nurse, a ship's engine worker, the navigator, the porter and the radio operator are all stuck together on a lifeboat with damaged water storage containers and spoiled rations. They don't know how long they'll be stuck there, or how they'll survive. And then they pick up one of the crewman from the U-boat that sank their ship.
Watching them interact is riveting as they flirt, carp, squabble and try to reason with each other. It's a taught, claustrophobic suspense film where questions of morality, decency and life and death are decided in a microcosm of society in a little boat on a big ocean. A masterpiece.