Sub Lieutenant

A Lieutenant, Junior Grade, is a division officer in the United States Navy. He or she leads a group of non-commissioned officers and enlisted personel in duties in weapons, engineering, and naval specialities. A Pilot Lieutenant, Junior Grade is promoted at a later date than his or her Surface Ship or Submarine fellow, because of training time. The time for promotion to Lieutenant, Junior Grade, is two to three years after joining the Fleet, Their Army, Air Force, and Marine Corps equals are First Lieutenants

In the Royal Navy and navies of many Commonwealth countries the rank is known as Sub Lieutenant

See Comparative military ranks and U.S. Navy Officer Rank Insignia