Ship prefixes generally refer to the abbreviations carved in front of the ship names, be it naval or merchant vessel, comprising of few letters compounded to denote a particular meaning. The prefixes can also refer to a few letters used to denote a particular fact.

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Ship prefixes used on merchant vessels are mainly to point out the propulsion technique employed in the ship, such as the abbreviation “SS” means “steamship”, indicating that the ship runs on steam propulsion. Ship prefixes can also include type of ship such as “RV” which denotes “research vessel”, and it affirms the purpose of the ship, which in this case is to acquire knowledge in a systematic and scientific manner. Merchant ship prefixes though frequent in usage, may differ in style, for instance, a slash can be introduced in between, viz. “M/S”.

Usage of abbreviations in Naval Ships

On the other hand, the naval ship prefixes are extensively used to shorten the longer titles into easy short forms for convenient utilization. The “His/Her Majesty’s Ship” are examples of the long titles used in the Royal Navy and thus the ship names such as H.M.S (or HMS) have come into common use.


MT – Motor Tanker

MV/MS – Motor vessel/Motor Ship

LB- Lifeboat

NS – Nuclear Ship

RV- Research Vessel

LPG/C – Liquefied Petroleum Gas Carrier

LNG/C – Liquefied Natural Gas Carrier

NS- Nuclear Ship

PSV- Platform Supply Vessel

MY- Motor Yacht

AHT- Anchor Handling Tug

CS – Cable Ship

DSV- Diving Support Vessel/ Deep Submerge Vessel

FV- Fishing Vessel

GTS- Gas Turbine Ship

RMS – Royal Mail Ship

SS- Steam Ship

PSV – Platform Support Vessel

TS- Training Ship

SV- Sailing Vessel

References for the Full List of Ship Prefixes:

Ship Prefixes – Wikipedia

Ship Acronyms

Naval nomenclature in some other countries

The Royal Navy from Netherlands, the English prefix used is “HLNMS” while the original Dutch one is “Hr.Ms” (or “Zr.Ms”). Since the Dutch names cannot be used on a broader platform or in documents written in English, the English ones are coined from the Dutch translations. In fact, it is a rule that unless a particular Dutch vessel from the Navy is launched into active service, it does not implement its ship prefixes. The ship name “NUSHIP” is used in Australia, to categorize the noncommissioned vessels in the fleet.

In the year of 1901, Theodore Roosevelt, the then President of United States passed a new law bill changing the agenda of the naval nomenclature of the country. Following which, a large number ship prefixes went out of use, except the ones like “USRC”, “USS”, “USNV” and “USNS”. Later on even “USRC” was declared obsolete and “USCGC” replaced it. This happened in 1915, when the Revenue Cutter Service had changed into the United States Coast Guard. A noncommissioned vessel in United States of America does not bear the right to use USS yet, and uses the “PCU” title meaning “Pre-Commissioned Unit”.

This implies, if a new aircraft-carrier vessel named Flattop is under construction in the US shipyard, it is continued to be called PCU Flattop till it receives commission. The “USS” prefix is only awarded when the vessel is introduced into active service in maritime sphere. According to the strict law, the United States Navy may not be able to buy foreign ships but can hire them under the United States Naval Vessels section.

It is a known observation that the United States Navy generally uses the ship prefixes without putting in articles, though an article “the” has been included in the “USS The Sullivans” vessel – as a tribute to the famous Sullivan brothers who lost their lives during the Second World War, and is an exceptional case of American ship nomenclature. Also, the equivalent British name of the vessel (“The HMS Flattop”) is not applicable as it would denote “The Her Majesty’s Ship” and it would be grammatically wrong.

Ship Prefix for retired ships

When a particular ship is declared out of active service, a prefix of “ex-” is attached in front of its name. This is done to separate the stricken vessel from any other vessel bearing the same name and in service, at that time. As an instance, the USS Constellation vessel (CV-64) came to be known as the “ex-Constellation” vessel after it accepted retirement in the year of 2003.

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Each country has a different method for naming both naval and merchant vessels using ship prefixes. However, some ship prefixes are most commonly used and accepted around the world.