Lieutenant commander is an officer rank in several navies.
In the Royal Navy, It is junior to commander and senior to the naval rank of lieutenant. Royal Navy ranks are matched up with Royal Air Force ranks. In this case the equivalent rank would be a squadron leader.
Lieutenant commander (LCDR) is a mid-ranking officer in the United States Navy, the United States Coast Guard, and several other public uniformed services.
In the Royal Canadian Navy, the rank of lieutenant commander (LCdr) (French: capitaine de corvette or capc) is the naval rank equal to major in the army or air force. It is the first rank of senior officer.
This rank would be usual for a commander of a minor warship, or an executive officer in a larger ship.