Alec reports aboard his ship, the destroyer USS Poe, at the Brooklyn Navy Yard, with no one to see him off as it departs for San Francisco. Meredith (James Whitmore), quickly takes a shine to Alec and he is befriended by his roommate and the ship's doctor, Lt. Edge (Keenan Wynn), has an immediate dislike of Alec's Quaker background and objects to his assignment as assistant gunnery officer.
Blanchard (Efrem Zimbalist Jr.), who soon realizes Alec is "carrying a torch" for Susan. Alec introduces himself to the sailors in the gunnery division, catching them gambling but overlooking the offense.
The climactic battle scene of the novel, a large scale surface action closely resembling the Battle of the Komandorski Islands, in the film became a minor land skirmish involving Austen's shore party during a rescue attempt.
Characters' traits and motivations were altered to match the personalities of the actors cast in the roles, or as in the case of Kennan Wynn's character, were a composite of two major characters. Jerry Mathers is seen in an uncredited role as one of the children of Susan's sister.
In San Francisco, Alec begins drawing a portrait of his Frenchy to give to his daughter.