A young navy officer is setting sail inspired by the wartime exploits of his grandfathers – who served on opposing sides in the Second World War.

Sub Lieutenant Ben Hoffmeister, 23, from Oxford, is following in the footsteps of the two men in pursuing a life at sea.

He will be aboard new patrol ship HMS Trent as it sets off for the Mediterranean next week.

Sub Lieutenant Hoffmeister’s grandfathers both fought in the bitter Battle of the Atlantic.

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.

After completing training as a mechanical engineer, Mr Menzel was assigned to U-963 and sailed on 10 war patrols out of bases in Norway and France in the final two years of the war.

This included a failed attempt to attack the Normandy invasion armada in June 1944.

Although a stoker, Mr Menzel manned one of the submarine’s anti-aircraft guns and was awarded the coveted Iron Cross for his part in an action against an RAF Liberator bomber – frequently the scourge of U-boats.

The submarine was eventually scuttled off the village of Nazare in Portugal 12 days after VE Day and Mr Menzel was taken prisoner with his shipmates.

He subsequently emigrated to Britain, where he settled down.

Sub Lieutenant Hoffmeister’s paternal grandfather Mr Hoffmeister was assigned to the Royal Naval Patrol Service after completing his training as a coder, serving with a converted trawler, HMT King Sol, in the Atlantic and Arctic before transferring to a destroyer based in Ceylon (today Sri Lanka) as the war against Japan reached its climax.

He died when Sub Lieutenant Hoffmeister was just 10 – with the future officer too young to have asked the questions he wished he could have about the war.

Sub Lieutenant Hoffmeister said: “One of the few stories I remember him talking about was having to climb up the mainmast during the convoys to chip off ice that had accumulated and risked capsizing the vessel.”

As for grandad Erwin, he was, says Sub Lieutenant Hoffmeister, “instrumental in raising my interest to join the navy”. He added: “By the time he died, when I was 17, I had already decided I was going to join the Royal Navy.”

It is unlikely, given where their vessels served and when, that his grandfathers faced each other in the Atlantic or Arctic, but his parents were nevertheless somewhat nervous when they met for the first time.

“They got on incredibly well when they eventually met,” he says. “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.”

And that post-war friendship will be echoed on Trent’s deployment when she works side-by-side with the German Navy on Nato duties on Operation Sea Guardian, the alliance’s counter-terrorism mission in the Mediterranean.

Lieutenant Commander David Webber, in charge of Trent’s marine engineering department, said: “It’s an interesting story from the perspective of how far Europe has come, with Ben now serving in the Royal Navy on a ship that will work alongside the modern Deutsche Marine.

“His family history acutely tracks the human impact of the history of 20th century Europe: World War 2, the division of Europe in the Cold War, reunification and co-operation.”