what does a lt commander do in the navy
Lieutenant commander A lieutenant commander is a senior department officer or the executive officer (second-in-command) on many warships and smaller shore installation, or the commanding officer of a smaller ship/installation.[6] They are also senior department officers in naval aviation squadrons.
Admiral of the Navy (United States) The Admiral of the Navy (abbreviated as AN) is the highest possible military rank in the United States Navy. The rank is intended as an "admiralissimo" type position which is senior to the rank of fleet admiral.
Lieutenant colonel (United States) In the United States Army, U.S. Marine Corps, and U.S. Air Force, a lieutenant colonel is a field grade military officer rank just above the rank of major and just below the rank of colonel. It is equivalent to the naval rank of commander in the other uniformed services.
Junior officer In the United States Armed Forces, the term junior officer is used by the Navy and the Coast Guard for officers in the ranks of ensign (O-1), lieutenant, junior grade (O-2), lieutenant (O-3), and lieutenant commander (O-4).