The Royal Navy is the principal naval warfare service branch of the British Armed Forces. As of August 2016, there are 77 commissioned ships in the Royal Navy. 19 of the commissioned vessels are major surface combatants (six guided missile destroyers and 13 frigates) and 11 are nuclear-powered submarines (four ballistic missile submarines and seven fleet submarines). In addition the Navy possesses a landing platform helicopter, two amphibious transport docks, 15 mine countermeasures vessels, 22 patrol vessels, four survey vessels, one icebreaker and two historic warships (Victory and Bristol).