Specialist soldiers offer force protection to US sub 

A US Navy nuclear-powered ballistic missile submarine is being guarded in Gibraltar by a specialist unit of Royal Marines whose primary job is to protect Britain’s strategic nuclear deterrent. 

The Ministry of Defence does not comment on submarine operations but the Chronicle understands the soldiers are from 43 Commando Fleet Protection Group, which normally operates from HM Naval Base Clyde on the west coast of Scotland, where the UK’s ballistic missile submarines are based. 

A team of specialist personnel was flown to Gibraltar together with heavily armed fast vessels that escorted the submarine into port on Sunday evening alongside the Gibraltar Squadron and the Gibraltar Defence Police. 

Yesterday, they provided security for the submarine within HM Naval Base Gibraltar, which was sealed off with a boom. A 200-metre exclusion zone is also in place around the South Mole. 

There is no confirmation on the identity of the Ohio-class submarine, although ship spotters speculated that it was the USS Alaska. 

Ohio-class submarines can patrol continuously as a key element of the US nuclear deterrence force and are designed specifically for stealth and the precise delivery of nuclear warheads, though some have been converted to carry up to 154 Tomahawk cruise missiles. 

Vessels of this type rarely surface after leaving port and the submarine’s presence in Gibraltar sends a clear signal about capability and underscores the Rock’s strategic role for the UK and its allies. 

On Monday, US Sixth Fleet Public Affairs confirmed the arrival of the submarine in a short statement that did not name the vessel.

“The port visit demonstrates US capability, flexibility, and continuing commitment to its NATO allies,” the statement said.

“Ohio-class ballistic missile submarines are undetectable launch platforms for submarine-launched ballistic missiles, providing the US with its most survivable leg of the nuclear triad.”

It is standard practice for the MOD to routinely authorise requests from a limited number of allies and partners to access UK bases, but details are rarely confirmed.

“For operational security reasons, we do not comment on foreign nations’ military operations, including their use of our bases," an MOD spokesperson said.

 The specialist Royal Marines guarding the vessel are no strangers to Gibraltar, having trained here on numerous occasions in the past and provided security when other ballistic missile submarines have called here. 

In 2023, for example, soldiers from 43 Commando Fleet Protection Group conducted Exercise Serpent Rock, which provided specific training focused around enhancing nuclear security capabilities. 

The aim of the exercise was to develop close quarter battle skills while working in the confines of a subterranean environment. 

Soldiers from the Royal Gibraltar Regiment also trained in Scotland alongside 43 Commando that same year. 

In an earlier exercise in 2020, soldiers from 43 Commando also added new tech to their training as part of the Future Commando Force modernisation, using drones and robots as they carried out amphibious operations, cliff assaults and close-quarters battle in the network of tunnels beneath the Rock.