Floating mines: LSs of fisherman's navy man rowing to floating mine, hightailing it away. Sequence on man calling Coast Guard, the latter answering, and dispatching a crew. Shots of cutter leaving. Men in rowboat approach gingerly, take mine in tow and manhandle it up on shore. After removing hatch, the experts set it on fire. HALS of fire, of tremendous explosion. Sequence on man measuring size of resulting crater.