The following is a list of current, officially-recognized ship hull designations utilized by the United States Navy as provided through the Naval Ship Register.
The classifications are generally representative of a given ship's role such as a Patrol Craft being "PC". Others, such as a Dock Landing Ship, are written as "LSD" and Tank Landing Ship follows as "LST". Ships like Destroyers and Frigates carry a double-letter identifier as in "DD" and "FF" respectively. To mark the change-over to nuclear-powered propulsion (from conventional power), warship types have introduced "N". For example Aircraft Carrier (originally marked as "CV") became "CVN". Nuclear-powered submarines evolved from the "SS" classification to "SSN".
The hull classification precedes the hull number as in USS Seawolf (SSN-21).
ACS = Auxiliary Crane Ship
AD = Destroyer Tender
AE = Ammunition Ship
AFS = Combat Shore Ship
AG = Auxiliary General
AGDS = Deep Submergence Support Ship
AGER = Environmental Research Ship
AGF = Miscellaneous Command Ship
AGM = Missile Range Instrumentation Ship
AGOR = Oceanographic Research Ship
AGOS = Ocean Surveillance Ship
AGS = Survey Ship
AGSS = Auxiliary Submarine
AH = Hospital Ship
AK = Cargo Ship
AKR = Vehicle Cargo Ship
AO = Oiler
AOE = Fast Combat Support Ship
AOG = Gasoline Tanker
AOR = Replenishment Oiler
AOT = Transport Oiler
AP = Transport
APD = High Speed Transport
AR = Repair Ship
ARC = Cable Repair Ship
AS = Submarine Tender
ARS = Salvage Ship
ASR = Submarine Rescue Ship
ATA = Auxiliary Ocean Tug
ATF = Fleet Ocean Tug
ATS = Salvage and Rescue Ship
AVB = Aviation Logistics Support Ship
AVT = Auxiliary Aircraft Landing Training Ship
BB = Battleship
CA = Cruiser, Armored
CB = Cruiser, Large
CC = Cruiser, Battle
CL = Cruiser, Light
CV = Cruiser, Aviation
CG = Cruiser, Guided Missile (conventional propulsion)
CGN = Cruiser, Guided Missile (nuclear propulsion)
CV = Aircraft Carrier (conventional propulsion)
CVN = Aircraft Carrier (nuclear propulsion)
DD = Destroyer Ship
DE = Destroyer Escort
DDG = Destroyer, Guided Missile
FF = Frigate
FFG = Frigate, Guided Missile
FFR = Frigate, Radar Picket
FFT = Frigate For Training
LCC = Amphibious Command Ship
LCH - Landing Craft, Heavy
LHA = Amphibious Assault Ship (General Purpose)
LHD = Amphibious Assault Ship (Multi-Purpose)
LPD = Amphibious Transport Dock
LPH = Landing Platform, Helicopter
LPR = High Speed Transport
LKA = Amphibious Cargo Ship
LSD = Landing Ship, Dock
LSM = Landing Ship, Medium
LST = Landing Ship, Tank
LST(H) = Landing Ship, Tank (Hospital)
MSO = Minesweeper, Ocean
MCM = Mine Countermeasures Ship
MCS = Mine Countermeasures Support Ship
MHC = Minehunter, Coastal
PC = Patrol Craft
PG = Patrol Combatant
PBL = Patrol Boat, Light
PBR = Patrol Boat, River
PCF = Patrol Craft, Fast (Swift Boat)
PGH = Patrol Combatant, Hydrofoil
PHM = Patrol, Hydrofoil, Missile
PTF = Patrol Boat, Fast
SS = Submarine (conventional propulsion)
SSGN = Guided Missile Submarine (nuclear propulsion)
SSM = Midget Submarine
SSN = Submarine (nuclear propulsion)
SSBN = Ballistic Missile Submarine (nuclear propulsion)
SST = Training Submarine