Senior Chief Boatswain's Mate Hobart Allen watches from a forecastle porthole as the starboard anchor is cleaned and raised after a precision anchoring exercise aboard the Nimitz-class aircraft carrier USS Harry S. Truman (CVN 75).

Aircraft carriers are warships that act as airbases for carrier-based aircraft. In the United States Navy, these consist of ships commissioned with hull classification symbols CV (aircraft carrier), CVA (attack aircraft carrier), CVB (large aircraft carrier), CVL (light aircraft carrier), CVN (aircraft carrier (nuclear propulsion) and CVAN (attack aircraft carrier (nuclear propulsion). The first aircraft carrier commissioned into the United States Navy was USS Langley (CV-1) on 20 March 1922.