Chidsey, Donald Barr "Three Times and You're Out."

Liberty “short, short story,” with a tag line which reads: “The kid thought he’d be afraid when the time came — but who can say just when fear gives way to courage. Set aboard a freighter in convoy off the coast of North Carolina, with the “kid” being a young wiper on his first voyage. He is naturally worried about how he may react in danger, and fears that he hasn’t the courage to face it if — and when — it comes. When the ship is torpedoed, he coolly remains at his engine room station and helps keep the vessel afloat until all his crew mates are able to abandon ship. Later, adrift in a lifeboat, the kid realizes that he’s cut out to be a mariner and decides to sign up for sea duty again as soon as he reaches land.