Submariners from HM Naval Base Clyde have been welcomed home by the UK's Deputy Prime Minister.

Oliver Dowden and the First Sea Lord, Admiral Sir Ben Key, were in Scotland to greet the Vanguard-class ballistic submarine on completion of their silent mission beneath the waves carrying the Trident missile system.

The Vanguard-class submarine was waved home by family members of the crew - with the boat's replacement already out on patrol to continue the Continuous At-Sea Deterrent.

Helensburgh Advertiser: Deputy prime minister and the first Sea Lord visit the submarineDeputy prime minister and the first Sea Lord visit the submarine (Image: Royal Navy)

Mr Dowden, said: “I am delighted to be here to welcome home our sailors as they return from patrol.

"The Continuous At Sea Deterrent is enormously important to the United Kingdom and I am humbled by their service.

"I do not underestimate the demands on our people and their families in their commitment to delivering this capability.”

Helensburgh Advertiser: The submariners were welcomed back to HMNB ClydeThe submariners were welcomed back to HMNB Clyde (Image: Royal Navy)

This is the 55th year of Operation Relentless, under which a British submarine carrying the nation’s ultimate weapon has patrolled the world’s oceans, unseen and undetected, since 1969.

Operation Relentless is the longest sustained military operation ever undertaken by the UK.

Admiral Key said: “It’s a great privilege for me to welcome home the returning ship’s company. They have done an exceptional job and I never fail to be impressed by their dedication and professionalism. I also pay immense tribute to their families and thank them for their support.

“We should never underestimate the huge national effort that goes into this endeavour."

A new class of ballistic submarine – the Dreadnought class – is currently under construction and is expected to replace the Vanguard-class by the 2030s.

Helensburgh Advertiser:

HMNB Clyde is on course to become the MoD's Single Integrated Operating Base (SIOB) – home to the entire UK submarine fleet.

That will comprise all four Vanguard-class submarines – and, in time, the new Dreadnought boats – and five Astute-class Royal Navy submarines, rising to seven when HMS Agamemnon and Agincourt join the fleet.

The Submarine Escape, Rescue, Abandonment and Survival (SMERAS) Facility is also based at Faslane, while development work is also under way on the Future Submarine School at the site.