A patrol ship has set sail to become the first Royal Navy vessel to be permanently based at Gibraltar.

HMS Trent departed from Portsmouth Naval Base heading to the Mediterranean where it will take on Nato duties as part of Operation Sea Guardian, the alliance’s counter-terrorism mission in the region.

The move to base the newly-commissioned vessel at the British Overseas Territory was revealed as part of the Government’s defence review revealed in Parliament last week.

The location will also enable 90-metre long (295ft) Trent to work alongside North African partners in counter-piracy operations in the Gulf of Guinea.

Trent is the third of five River Class offshore patrol vessels and it made its first operational deployment to Gibraltar in August last year following its commissioning into service.

The Clyde-built ship, which has a range of 5,000 miles, and can remain at sea for 320 days of the year, is designed to conduct operations with Merlin helicopters.

Among the ship’s 65-strong crew heading to Gibraltar is Sub Lieutenant Ben Hoffmeister, 23, from Oxford, who is following in the footsteps of his two grandfathers who fought on both sides in the bitter Battle of the Atlantic in the Second World War.

Ernest Hoffmeister served in the Atlantic and Arctic determined to keep the UK’s sea lanes open, while Sub Lieutenant Hoffmeister’s maternal grandfather Erwin Menzel crewed a U-boat determined to strangle Britain’s lifelines.

Sub Lt Hoffmeister said his grandfather Erwin was “instrumental in raising my interest to join the navy”.

He added: “They got on incredibly well when they eventually met. It seemed the shared experience of the Battle of the Atlantic was more important to them than which side of the war they had fought it on.

“That legacy is perhaps the most important aspect to take away from their story.”