Ship prefix
A ship prefix is a combination of letters, usually abbreviations, used in front of the name of a civilian or naval ship that has historically served numerous purposes, such as identifying the vessel's mode of propulsion, purpose, or ownership/nationality. In the modern environment, prefixes are cited inconsistently in civilian service, whereas in government service a vessel's prefix is seldom omitted due to government regulations dictating that a certain prefix be used. Today the common practice is to use a single prefix for all warships of a nation's navy, and other prefixes for auxiliaries and ships of allied services, such as coast guards. For example, the modern navy of Japan adopts the prefix "JS" – Japanese Ship, or the US navy has adopted the USS prefix. However, not all navies use prefixes. Among the blue-water navies, those of France, Brazil, China, Russia, Germany, Ukraine, and Spain do not use ship prefixes. NATO designations such as FS, FGS, and SPS can be used if needed.
Usage
Historically, prefixes for civilian vessels often identified the vessel's mode of propulsion, such as "MV", "SS", or "PS".These days, general civilian prefixes are used inconsistently, and frequently not at all. In terms of abbreviations that may reflect a vessel's purpose or function, technology has introduced a broad variety of differently named vessels onto the world's oceans, such as "LPGC", or "TB", or "DB". In many cases though, these abbreviations are used for purely formal, legal identification and are not used colloquially or in the daily working environment. Prefixes indicating a vessel's purpose are also used.
Prefixes used for naval ships primarily reflect ownership, but may also indicate a vessel's type or purpose as a sub-set. Historically, the most significant navy was Britain's Royal Navy, which has usually used the prefix "HMS", standing for "His/Her Majesty's Ship". The Royal Navy also adopted nomenclature that reflected a vessel's type or purpose, e.g. HM Sloop. Commonwealth navies adopted a variation, with, for example, HMAS, HMCS, and HMNZS pertaining to Australia, Canada, and New Zealand, respectively.
In the early days of the United States Navy, abbreviations often included the type of vessel, for instance "USF", but this method was abandoned by President Theodore Roosevelt's Executive Order No. 549 of 1907, which made "United States Ship" the standard signifier for USN ships on active commissioned service. United States Navy prefixes officially only apply while a ship is in active commission, with only the name used before or after a period of commission and for all vessels "in service" rather than commissioned status.
However, not all navies used prefixes; this includes the significant navies of China, France and Russia.
From the 20th century onwards, most navies identify ships by letters or hull numbers or a combination of such. These identification codes were, and still are, painted on the side of the ship. Each navy has its own system: the United States Navy uses hull classification symbols, and the Royal Navy and other navies of Europe and the Commonwealth use pennant numbers.
These tables list both current and historical prefixes known to have been used.
Generic (merchant navy) prefixes
These prefixes are generally used for merchant vessels of any nationality unless specified.| Prefix | Meaning |
| AE | Ammunition ship |
| AFS | Combat stores ship |
| AHT | Anchor handling tug |
| AHTS | Anchor handling tug supply vessel |
| AO | United States Navy oiler |
| AOG | Gasoline tanker |
| AOR | Auxiliary replenishment oiler |
| AOT | Transport oiler |
| ASDS | Autonomous Spaceport Drone Ship |
| ATB | Articulated Tug Barge |
| CRV | Coastal Research Vessel |
| C/F | Car ferry |
| CS | Container ship or Cable ship |
| DB | Derrick barge |
| DEPV | Diesel Electric Paddle Vessel |
| DLB | Derrick Lay Barge |
| DCV | Deepwater Construction Vessel |
| DSV | Diving support vessel or deep-submergence vehicle |
| DV | Dead vessel |
| ERRV | Emergency Response Rescue Vessel |
| EV | Exploration Vessel |
| FPSO | Floating production storage and offloading vessel |
| FPV | Free Piston Vessel |
| FPV | Fishery Protection Vessel |
| FT | Factory Stern Trawler |
| FV | Fishing Vessel |
| GTS | Gas Turbine Ship |
| HLV | Heavy lift vessel |
| HMT | Hired military transport |
| HMHS | His Majesty's Hospital Ship |
| HSC | High Speed Craft |
| HSF | High Speed Ferry |
| HTV | Heavy transport vessel |
| IRV | International Research Vessel |
| ITB | Integrated Tug barge |
| LB | Liftboat |
| LNG/C | Liquefied natural gas carrier |
| LPG/C | Liquefied petroleum gas carrier |
| MF | Motor ferry |
| MFV | Motor fishing vessel |
| MS | Motor ship |
| MSV | Multipurpose support/supply vessel |
| MSY | Motor Sailing Yacht |
| MT | Motor Tanker |
| MTS | Marine towage and salvage/tugboat |
| MV | Motor Vessel |
| MY | Motor Yacht |
| NB | Narrowboat |
| NRV | NATO Research Vessel |
| NS | Nuclear ship |
| OSV | Offshore supply vessel |
| PS | Paddle steamer |
| PSV | Platform supply vessel |
| QSMV | Quadruple screw motor vessel |
| QTEV | Quadruple turbo electric vessel |
| RMP | Royal Mail Packet |
| RMS | Royal Mail Ship or Royal Mail Steamer |
| RMV | Royal Mail Vessel |
| RNLB | Royal National Lifeboat |
| RNMB | Royal Navy Motor Boat |
| RRS | Royal Research Ship |
| RV / RSV | Research vessel/Research Survey Vessel |
| SB | Sailing Barge |
| SL | Steam Launch |
| SS | Single-screw steamship |
| SSCV | Semi-submersible crane vessel |
| SSS | Sea Scout Ship |
| SSV | Sailing School Vessel, or Submarine and Special Warfare Support Vessel |
| ST | Steam tug or Steam trawler |
| STS | Sail training ship |
| STV | Sail Training Vessel or Steam Turbine Vessel |
| SV | Sailing Vessel |
| SY | sailing yacht or steam yacht |
| TB | Tug boat |
| TIV | Turbine Installation Vessel |
| TEV | Turbine electric vessel |
| TrSS | Triple-screw steamship or steamer |
| TS | Training Ship or turbine steamship or turbine steam ship |
| Tr.SMV | Triple-Screw Motor Vessel |
| TSMV | Twin-Screw Motor Vessel |
| TSMS | Twin-Screw Motor Ship |
| TSS | Twin-screw steamship or steamer |
| TST | Twin-screw tug |
| TT | "Tender to"..., the prefix is placed on the tender followed by the name of the mother ship; or Turbine Tanker |
| TV | Training vessel |
| ULCC | Ultra Large Crude Carrier |
| VLCC | Very Large Crude Carrier |
| YD | Yard derrick |
| YT | Yard Tug |
| YMT | Yard Motor Tug |
| YTB | Yard Tug Big |
| YTL | Yard Tug Little |
| YTM | Yard Tug Medium |
| YW | Water barge, self-propelled |
| YWN | Water barge, non-propelled |
National or military prefixes
| Country | Service | Prefix | Meaning |
| Albanian Naval Force | ALS | Albanian Ship | |
| Algerian National Navy | ANS | Algerian Navy Ship | |
| Argentine Navy | ARA | Navy of the Argentine Republic '' | |
| Argentine Coast Guard | GC | Argentine Coast Guard Ship | |
| Royal Australian Navy | HMAS | His Majesty's Australian Ship/Submarine/Station | |
| Royal Australian Navy | NUSHIP | New Ship/Submarine | |
| Royal Australian Navy | ADV | Australian Defence Vessel | |
| Royal Australian Navy | MSA | Minesweeper Auxiliary | |
| Australian Customs and Border Protection Service | ACV | Australian Customs Vessel | |
| Australian Border Force | ABFC | Australian Border Force Cutter | |
| Australia | Colonial navies of Australia | HMCS | His Majesty's Colonial Ship |
| Australia | Colonial navies of Australia | HMQS | His Majesty's Queensland Ship |
| Australia | Colonial navies of Australia | HMVS | His Majesty's Victorian Ship |
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