Jack Mason meets Mary Trumbull at a Coast Guard Academy graduation ball and falls in love with her. However, the girl's mother considers wealthy Rex Cutting a more appropriate choice for her daughter. During a yachting cruise arranged by Mrs. Trumbull, Mary refuses Rex's marriage proposal, as she suspects him of being a bootlegger. Meanwhile Betty, Mary's impish sister, drives Skippy Dugan to distraction in the galley, where he has installed an automatic kitchen that does most of his work. Jack smuggles himself aboard but is forcibly ejected at port, and Mrs. Trumbull discourages his attempt to elope with Mary. On a subsequent cruise, Jack hides in a lifeboat with two fellow Coast Guard members, and they witness the captain take on a cargo of illicit rum. Jack and his aides attempt to commandeer the vessel and a battle ensues. The yacht is wrecked on an island, where Jack proves his heroism and Rex is revealed as a fugitive bootlegger.