Answer: USS

AnswerCrossword Clue
USSNaval cruiser letters
USSBattleship initials
USSCapt. Kirk's .. Enterprise
USSConstitution beginning?
USSFleet letters
USS.. Ronald Reagan
USSBattleship inits.
USSSub letters
USS.. Enterprise
USSAmer. ship designation
USSLetters at sea
USSSeagoing letters
USS.. Constitution
USS.. Nautilus
USSNavy ship letters
USSLetters on the Ronald Reagan
USSNimitz letters
USSCarrier letters
USS.. Intrepid
USS.. Arizona
USSLetters before Kitty Hawk
USS"Constitution" inits.
USSConstitution preceder
USS"Enterprise" letters
USSDestroyer letters
USS... Ronald Reagan
USSAmerican vessel's letters
USSVessel insignia
USSConstitution abbr.
USSEnterprise letter
USS"Arizona" letters
USSBattleship letters
USSNaval letters
USSShip letters
USSBroadside initials
USS... Constitution (historic frigate)
USS... Monitor (Civil War ironclad)
USS...Constitution, nicknamed "Old Ironsides"
USSNavy-vessel letters
USSLiner letters