What Does SS Stand for on Ships?

What does SS stand for on ships? We have the answers! This guide explains common ship abbreviations and their meanings.

In the maritime world, abbreviations and acronyms differentiate various types of ships. These abbreviations make it easier to know which kind of ship is being discussed and can reflect a ship’s purpose, historical significance, or even which country it belongs to.

Today, we are going to answer what SS stands for on ships. Not only will we provide an answer and explain the historical significance of the abbreviation, but we will also look at the origins and meaning of some of the other common abbreviations and ship prefixes.

What Does SS Stand for on Ships?

Regarding ships, the abbreviation SS is short for “steamship.” Traditionally, the term described any ship that used a steam engine to power its primary propulsion system.

These types of engines were incredibly common in the 19th century and into the early 20th century. Steam engines completely changed the face of the maritime world, as they could propel ships through the water without relying on the wind blowing against sails or man-powered oars.

What Does S.S. Stand for on Ships?

While it may seem somewhat confusing, the SS prefix denotes a steamship, while the abbreviation S/S or S.S. refers to a “sailing ship.” Although the two abbreviations may look and sound similar, they refer to two distinct types of vessels.

Sailing Ship
Photo Credit: true north 72 / Shutterstock

What Does USS Stand for on Ships?

USS stands for “United States Ship.” It is the official title given to ships that belong to the United States Navy. Like the other abbreviations and acronyms, the prefix USS is followed by the ship’s unique name. USS can be attached to smaller vessels operated by the United States Navy and the largest aircraft carriers.

What Does HMS Stand for on Ships?

Another maritime term you may have come across is HMS. This acronym stands for “Her/His Majesty’s Ship.” HMS tends to be used by the British Royal Navy to separate warships that belong to the Crown from civilian ships or those belonging to another nation’s navy.

H.M.S. Belfast
H.M.S. Belfast (Photo Credit: Danny Ye / Shutterstock)

You may have seen this particular acronym on the sides of famous warships, as Britain’s Royal Navy was the most powerful navy on the planet from the mid-18th century until shortly after the Second World War!

While this acronym tends to be used almost exclusively by the Royal Navy in Great Britain, it can also be used to designate any ship owned or operated by the British monarchy or government. Today, it is still used often, including for the newest ships in the fleet.

What Does RMS Stand for on Ships?

You may have also encountered the acronym RMS while studying some of the more famous vessels in history. While it may surprise you, RMS stands for Royal Mail Ship. 

This designation was given to any ship tasked with carrying mail under the contract of Britain’s Royal Mail service. Given that the written letter was one of the only ways to communicate with those in other parts of the world, being trusted with mail delivery was a great honor. A ship had to be fast, efficient, and reliable to be trusted with the task.

Titanic Voyage
Titanic Voyage

One of history’s most famous ships actually carried the RMS designation: the RMS Titanic. While the Titanic is primarily known as a luxury passenger ocean liner, it also was designed to transport mail between Europe and North America, hence the RMS designation.

Frequently Asked Questions

Do cruise ships have their own abbreviation or acronym?

Cruise ships rarely receive a standardized abbreviation or acronym. A merchant or navy abbreviation is unnecessary since these ships are designed almost exclusively for leisure and enjoyment. Instead, the cruise line that owns the passenger liner can give it any name they choose.

Is the SS abbreviation still used for ships today?

The SS designation is rarely given to ships today because few ships, aside from historical recreations, are powered by steam engines, so they would not be designated as a “steamship.”

Does every country use the same abbreviations for ships?

No, each country tends to have its own abbreviations for various types of ships. While some of the most popular and widely recognized, like SS, are nearly universal, each country and its navy tends to have its own terminology.

Other common abbreviations most countries use include MV, which stands for “Motor Vessel,” and RV, which designates a “Research Ship.”

Final Words

SS and other popular maritime abbreviations, like USS, HMS, and RMS, can carry important historical meanings, or they can be used for more practical reasons, such as making it easy to identify whether a ship belongs to a navy or is civilian-owned.

Read Also: What is the Steering Wheel on a Ship?

Today, these abbreviations are less important and prominent than they were at the turn of the previous century, but it is still worth familiarizing yourself with their meanings, especially if you are interested in maritime history and culture.

Emrys Thakkar
Emrys Thakkar
The founder of Cruise Hive which was established in 2008 as one of the earliest cruise blogs in the industry. Emrys has been reporting on the latest cruise industry news since the site first launched. Expert insights and tips featured on a number of publications including The Express, Business Insider, and more. Worked for Carnival Cruise Line for 8 years and is well and truly dedicated to cruising! Has also been on a number of cruises so can offer an insight into the industry that many will not be able to do. What's even more impressive is that Emrys has traveled the world by visiting more than 34 countries, lived in China for 8 years, and cruised the Caribbean, Baltic, Mediterranean, Asia, and Europe. Find out more about us here.


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