The Frogmen (1951)
Action/war film about a commanding officer assigned to replace the well-liked commanding officer of a Navy underwater demolition team, who died in combat. The new commander starts out with a strict no-nonsense approach which the men under his command see as being too rigid and impersonal. He eventually relaxes his demeanor and proves himself to be a selfless leader, earning the respect of the rest of his men and the crew aboard the ship they are assigned to.