Submarines by Country 2025

A submarine (“sub” for short) is a watercraft capable of operating completely underwater. Submarines have multiple civilian uses, such as tourism, undersea archaeology, facility inspection and maintenance, and marine science, salvage, and exploration. Subs also perform many vital military functions, including attacking enemy watercraft above and below the surface, protecting friendly aircraft carriers and other ships, acting as a nuclear strike force, blockade running, reconnaissance, and more.

Modern Military Submarine Fleets

Today, many national navies maintain a fleet of five or more submarines, both large and small, whose main role is to act as a deterrent in territorial waters. The United States Navy utilizes three types of submarine: ballistic missile submarines, attack submarines, and cruise missile submarines. Global Fire Power tracks the most recent data on each nation’s number of naval submarines. Landlocked countries typically do not have a standing navy and, therefore, do not have submarines. Those countries were not included in GFP’s rankings. The rankings are also combined totals and do not take into account each submarines’ type, size, age, military function, or construction quality.

Top 10 Countries with the Largest Military Submarine Fleets (Global Firepower 2024)

It should be noted, however, that the GFP list differs significantly from a similar ranking released by the International Institute of Strategic Studies.

Military Use of Submarines throughout History

The first documented use of a submersible in combat occurred on September 7, 1776, during the American Revolutionary War. On that date, an eight-foot-long, hand-powered sub christened the Turtle was used in an attempt to attach a bomb to a British Royal Navy vessel in New York Harbor.

The attempt was unsuccessful, owing to the fact that submarine technology was still in its infancy. Despite many creative approaches to submarine design, efforts to use subs in combat met with limited success during this and many subsequent conflicts. Submarines would, however, come into wide military use starting with World War I, some 130+ years later.

In World War II, submarines proved to be very effective and deadly contributors to the war effort. Germany used submarines to cut off Britain’s supply route by sinking merchant ships. The Imperial Japanese Navy operated the most diverse fleet of submarines in the war, including midget submarines, medium-range submarines, and long-range fleet submarines. Japan also deployed the fastest subs, subs that could carry multiple aircraft, and subs equipped with the most advanced torpedoes.