A commissioned officer of the United States Navy whose rank is above an ensign's and below a lieutenant, or a corresponding rank in other navies.
A commissioned officer in the United States Coast Guard, Public Health Service, or National Atmospheric and Oceanic Administration whose rank is above an ensign and below a lieutenant.
A commissioned officer of the navy ranking above an acting sub-lieutenant and below a lieutenant.
A commissioned officer of the Royal Navy ranking above a midshipman and below a lieutenant.