The United States Navy uses hull classification symbols to identify the types of its ships. See also pennant number, a somewhat analogous system used by the Royal Navy and some European navies.

The combination of symbol and hull number identify a modern Navy ship uniquely. A heavily modified or repurposed ship may receive a new symbol, and either retain the hull number or receive a new one. Also, the system of symbols has changed a number of times since it was introduced in 1907, so ships' symbols sometimes change without anything being done to the physical ship.

Many of these symbols are not presently in use.

Table of contents
1 Warships
2 Support Ships

Warships

Warships are designed to participate in combat operations.

Aircraft Carrier Type

All ships designed primarily for the purpose of conducting combat operations by aircraft which engage in attacks against airborne, surface, sub-surface and shore targets. The V has an lost meaning.

  • CV Multi-purpose Aircraft Carrier
  • CVA Attack Aircraft Carrier
  • CVB Battle (large) Aircraft Carrier
  • CVE Escort aircraft carrier (retired)
  • CVL Light Aircraft Carrier
  • CVN Multi-purpose Aircraft Carrier (Nuclear-Propulsion)
  • CVS Antisubmarine Aircraft Carrier

Surface Combatant Type

Large, heavily armed, surface ships which are designed primarily to engage enemy forces on the high seas.

Submarine Type

All self-propelled submersible types regardless of whether employed as combatant, auxiliary, or research and development vehicles which have at least a residual combat capability.

  • SF Fleet Submarine (retired)
  • SS Submarine
  • SSK Hunter-Killer Submarine
  • SSN Attack Submarine (Nuclear-Powered)
  • SSBN Ballistic Missile Submarine (Nuclear-Powered)
  • SSGN Guided (Cruise) Missile Submarine (Nuclear-Powered)
  • SSRN Radar Picket Submarine (Nuclear-Powered)
  • SST Training Submarine
  • SSG Conventionally Powered Guided Missile Submarine

Patrol Combatant Type

Combatants whose mission may extend beyond coastal duties and whose characteristics include adequate endurance and sea keeping providing a capability for operations exceeding 48 hours on the high seas without support.

Amphibious Warfare Type

All ships having organic capability for amphibious assault and which have characteristics enabling long duration operations on the high seas.

  • LHA Amphibious Assault Ship (General Purpose)
  • LHD Amphibious Assault Ship (Multi-Purpose)
  • LPD Amphibious Transport Dock
  • LPH Amphibious Assault Ship (Helicopter)
  • LKA Amphibious Cargo Ship
  • LSD Dock Landing Ship
  • LSM Medium Landing Ship
  • LST Tank Landing Ship
  • LCC Amphibious Command Ship

Combat Logistics Type

Ships which have the capability to provide underway replenishment to fleet units.

  • AE Ammunition Ship
  • AFS Combat Store Ship
  • AO Oiler
  • AOE Fast Combat Support Ship
  • AOR Replenishment Oiler

Mine Warfare Type

All ships whose primary function is mine warfare on the high seas.

Coastal Defense Type

All ships whose primary function is coastal patrol and interdiction.

  • PC Patrol, Coastal

Mobile Logistics Type

Ships which have the capability to provide direct material support to other deployed units operating far from home base.

  • AD Destroyer Tender
  • AR Repair Ship
  • AS Submarine Tender

Support Ships

Support ships are not designed to participate in combat, and are generally not armed.

Support Type

A grouping of ships designed to operate in the open ocean in a variety of sea states to provide general support to either combatant forces or shore based establishments. (Includes smaller auxiliaries which by the nature of their duties, leave inshore waters).

  • ARS Salvage Ship
  • ASR Submarine Rescue Ship
  • ATA Auxiliary Ocean Tug
  • ATF Fleet Ocean Tug
  • ATS Salvage and Rescue Ship
  • ACS Auxiliary Crane 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 Surveying Ship
  • AGSS Auxiliary Research Submarine
  • AH Hospital Ship
  • AK Cargo Ship
  • AKR Vehicle Cargo Ship
  • AOG Gasoline Tanker
  • AOT Transport Oiler
  • AP Transport
  • APD High Speed Transport
  • ARC Cable Repair Ship
  • AVB Aviation Logistics Support Ship
  • AVT Auxiliary Aircraft Landing Training Ship

Service Type Craft

A grouping of navy-subordinated craft (including non-self-propelled) designed to provide general support to either combatant forces or shore-based establishments.

  • AFDB Large Auxiliary Floating Dry Dock
  • AFDL Small Auxiliary Floating Dry Dock
  • AFDM Medium Auxiliary Floating Dry Dock

  • ARD Auxiliary Repair Dry Dock
  • ARDM Medium Auxiliary Repair Dry Dock

  • YFD Yard Floating Dry Dock
  • YTB Large Harbor Tug
  • YTL Small Harbor Tug
  • YTM Medium Harbor Tug

  • YO Fuel Oil Barge
  • YOG Gasoline Barge
  • YW Water Barge

  • YF Covered Lighter
  • YFR Refrigerated Cover Lighter
  • YFU Harbor Utility Craft
  • YG Garbage Lighter

  • YC Open Lighter
  • YCF Car Float
  • YCV Aircraft Transportation Lighter
  • YFN Covered Lighter
  • YFNB Large Covered Lighter
  • YFNX Lighter (Special purpose)
  • YFRN Refrigerated Covered Lighter
  • YFRT Range Tender
  • YGN Garbage Lighter
  • YOGN Gasoline Barge
  • YON Fuel Oil Barge
  • YOS Oil Storage Barge
  • YSR Sludge Removal Barge
  • YWN Water Barge

  • DSRV Deep Submergence Rescue Vehicle
  • DSV Deep Submergence Vehicle

  • NR Submersible Research Vehicle

  • YFB Ferry Boat or Launch
  • YM Dredge
  • YP Patrol Craft, Training
  • YSD Seaplane Wrecking Derrick
  • YTT Torpedo Trials Craft

  • APL Barracks Craft

  • YD Floating Crane
  • YDT Diving Tender
  • YFND Dry Dock Companion Craft
  • YFP Floating Power Barge
  • YLC Salvage Lift Craft
  • YMN Dredge
  • YNG Gate Craft
  • YPD Floating Pile Driver
  • YR Floating Workshop
  • YRB Repair and Berthing Barge
  • YRBM Repair, Berthing and Messing Barge
  • YRDH Floating Dry Dock Workshop (Hull)
  • YRDM Floating Dry Dock Workshop (Machine)
  • YRR Radiological Repair Barge
  • YRST Salvage Craft Tender

  • IX Unclassified Miscellaneous Unit
  • X Submersible Craft

The USS Constitution, formerly IX 21, was reclassified to none, effective September 1, 1975.