Submarine Bases — The World's Most Strategic Naval Installations

Home to the US Atlantic Fleet's ballistic missile submarines and the Strategic Weapons Facility Atlantic (SWFLANT), where Trident II D5 missiles are assembled, maintained, and loaded onto submarines. Kings Bay provides the eastern seaboard's contribution to America's nuclear deterrent. The base covers 16,000 acres and employs over 10,000 military and civilian personnel. Submarines depart through the St. Marys River and Cumberland Sound to reach the Atlantic.

The largest concentration of nuclear warheads in the US arsenal. Bangor hosts 8 Ohio-class SSBNs carrying Trident missiles, 2 Ohio-class SSGNs carrying Tomahawk cruise missiles, and several fast-attack submarines. The Strategic Weapons Facility Pacific (SWFPAC) stores and maintains the Trident missile arsenal. Located on the Kitsap Peninsula on Puget Sound, it provides rapid access to the Pacific Ocean.

The first and oldest submarine base in the US Navy, and home to the Naval Submarine School where all US submarine officers and enlisted personnel are trained. Adjacent to Electric Boat (General Dynamics), the primary builder of US submarines since 1899. Nearly every class of US submarine has been built or based here. The base also houses the Submarine Force Library and Museum, including the historic USS Nautilus (SSN-571).

Her Majesty's Naval Base Clyde is the home of the entire UK submarine fleet and the sole operating base for Britain's nuclear deterrent. At least one Vanguard-class SSBN is always on patrol — Continuous At-Sea Deterrence (CASD) has been maintained unbroken since 1969. The Royal Naval Armaments Depot at Coulport, across Loch Long, stores and loads Trident warheads. Faslane will host the new Dreadnought-class SSBNs from the late 2030s.

France's Force oceanique strategique (FOST) — the sea-based nuclear deterrent — operates from Ile Longue, a heavily fortified peninsula in the Rade de Brest. The base houses all four Triomphant-class SSBNs carrying M51 ballistic missiles. Like the UK, France maintains continuous at-sea deterrence with at least one SSBN always on patrol. The base includes missile storage, warhead assembly facilities, and extensive security zones.

Russia's primary base for ballistic missile submarines, located on the Kola Peninsula above the Arctic Circle. Gadzhiyevo hosts the Northern Fleet's SSBN force — the most powerful element of Russia's nuclear triad. The base provides access to the Barents Sea and the Arctic Ocean, allowing SSBNs to patrol in "bastion" areas protected by Russian naval and air forces. During the Cold War, Soviet SSBNs would transit through the GIUK Gap to reach the Atlantic.

China's most important and secretive submarine base, located on the southern tip of Hainan Island. Satellite imagery has revealed massive underground tunnel complexes capable of sheltering nuclear submarines from surveillance and strike. The base provides direct access to the deep waters of the South China Sea, allowing SSBNs to reach patrol depths quickly without transiting through shallow, monitored waters. The base has been massively expanded since 2010.

Australia's primary submarine base on Garden Island in Cockburn Sound, Western Australia. Currently home to the six Collins-class diesel-electric submarines. Under the AUKUS agreement, HMAS Stirling will undergo massive expansion to host nuclear-powered SSN-AUKUS submarines from the 2030s, including a rotational presence of US Virginia-class and UK Astute-class submarines starting as early as 2027. The base is being upgraded with nuclear-certified maintenance and support facilities.

What is the largest submarine base in the world?

Naval Submarine Base Kings Bay in Georgia, USA, is one of the largest, serving as the home port for the US Atlantic Fleet's Ohio-class ballistic missile submarines. It covers over 16,000 acres and includes the massive Strategic Weapons Facility Atlantic (SWFLANT) where Trident missiles are assembled and loaded. Russia's Gadzhiyevo base on the Kola Peninsula is the largest Russian submarine base, hosting the Northern Fleet's SSBNs.

Why are submarine bases kept secret?

Submarine bases — especially those housing ballistic missile submarines — are among the most sensitive military installations in any country. The location of SSBNs is critical to nuclear deterrence; if an enemy could destroy all submarines in port, it could theoretically eliminate a nation's sea-based nuclear capability. However, base locations themselves are generally known — it's the patrol areas and operating schedules that are the most closely guarded secrets.

What is China's underground submarine base at Yulin?

The Yulin Naval Base on Hainan Island, China, includes massive underground caverns carved into hillsides that can shelter nuclear submarines from satellite surveillance and potential attack. Commercial satellite imagery has revealed tunnel entrances large enough for submarines, underground pens, and supporting infrastructure. The base houses both nuclear attack submarines (SSNs) and ballistic missile submarines (SSBNs), and provides direct deep-water access to the South China Sea.

Can a submarine base survive a nuclear attack?

Some submarine bases are hardened against nuclear attack. The Soviet/Russian base at Balaklava in Crimea was built inside a mountain to survive a direct nuclear strike. Norway's Olavsvern base featured underground tunnels for submarine repair. However, most modern submarine bases rely on dispersal rather than hardening — the submarines themselves are the survivable force, designed to be at sea on patrol when conflict begins, not sitting in port.

What is CASD and why does Faslane matter?

CASD stands for Continuous At-Sea Deterrence — the UK policy of maintaining at least one ballistic missile submarine on patrol at all times since 1969. HMNB Clyde at Faslane, Scotland, is the home port of all UK Vanguard-class SSBNs (and future Dreadnought-class). If Faslane were lost, the UK's entire nuclear deterrent would be at risk, making it arguably the most strategically important single military installation in Britain.

How many submarine bases does the US Navy operate?

The US Navy operates several major submarine bases: Naval Submarine Base Kings Bay (Georgia) for Atlantic SSBNs, Naval Base Kitsap-Bangor (Washington) for Pacific SSBNs, Naval Submarine Base New London/Groton (Connecticut) as the "Submarine Capital of the World," Pearl Harbor (Hawaii) for Pacific SSNs, and Naval Station Norfolk (Virginia). Additional submarines are based at San Diego and Guam.