Minesweeper (1943)

"DANGER AFLOAT! ABOVE, BELOW AND ACROSS THE SEAS...WITH THE HEROIC MEN OF THE COAST GUARD!"

A naval officer who had deserted several years earlier is drawn back to the Navy when World War II begins. He re-enlists under an assumed name, and is assigned to a minesweeper, where he has to perform hazardous duties while at the same time keeping his real identity a secret.