Naval Officer, for short, can be abbreviated to two four-letter terms: EXEC and BOSN. EXEC stands for Executive Officer, which is the second in command of a naval vessel. The Executive Officer is responsible for the day-to-day operations of the ship and reports directly to the commanding officer. BOSN stands for Boatswain, which is a senior enlisted rank in the Navy. The Boatswain is responsible for the maintenance and upkeep of the ship, as well as supervising the crew.