A ceremony has taken in the French port of St Nazaire as the last remaining veterans gather to remember one of the most daring raids of World War II.
From the start of 1941, the new German battleship the Tirpitz was the subject of enormous concern for Winston Churchill and the top brass in Britain.
The fear was that the newly built ship could target the Atlantic convoys that were the vital lifeline for Britain.
But there was only one place on the Atlantic seaboard where it could be repaired - the enormous Normandie dock at St Nazaire in France.
If that could be put out of action then London was sure that Hitler would not risk sending his prize vessel to menace the Atlantic.
But the question was how to destroy the dock? RAF bombs were not accurate enough to hit the gate.
So, a plan of brain-bending ambition was drawn up. An old ship - HMS Campbeltown - would be remodelled to look like a German vessel.
A four-and-a-half-ton bomb would be hidden on board, and the ship would be packed with British commandos.
Then it would sail up six miles up the Loire estuary, past 80 German emplacements towards the dock.
When it arrived at the 1,500-ton gate, the commandos would jump off, destroy as much as they could and distract attention until the bomb did its work.
Next to the dock were 14 U-Boat pens, and 5,000 German troops guarded the town.
The attackers were supposed to escape on wooden boats which had accompanied the destroyer.
It was called Operation Chariot. Corran Purdon - then aged 20 - was one of those commandos selected to take part.
"I thought it was going to be a pretty dicey do, to be honest - but I never thought we wouldn't do it," he told me on the 70th anniversary.
The commandos had barely been deployed so far in the war and were itching to take part in the action.
On the night of 28 March 1942, the Campbeltown made it part way up the estuary before the Germans discovered the ruse - and searchlights and tracer fire lit up the night sky.
In a remarkable piece of seamanship, the ship, despite one wrong turn, hit the dock gates dead on just after 01:30.
The commandos inside were braced to absorb the impact but recall a long shuddering reverberation rather than a short sharp shock as the ship drove into the gates.
Mr Purdon - who was a lieutenant at the time - and four corporals were tasked with blowing up one of the two winding houses.
He jumped off the ship carrying a rucksack full of explosives. Bullets whipped past.
As he made it to the building, he was surprised to discover it locked.
Improvising, he pulled out his Colt 45 revolver and pointed it at the lock.
The bullet ricocheted off, just missing one of his corporals.
"You know, sir, when I came on this raid, I was quite prepared to get murdered by Adolf Hitler, but not by you, sir," the man told Mr Purdon, before pulling out a mallet to smash the lock.
It took 15 minutes to lay the charges, during which time Mr Purdon kept his men going with a limerick.
When the charge finally blew, the winding house rose up into the air before collapsing like a house of cards.
"Ready to return to England," Mr Purdon told his colonel.
But the colonel pointed out to the water, filled with burning wooden boats.
"There's been a problem with the transport," he said, before issuing orders to his men to fight through town and head for the Spanish border - hundreds of miles away - and then on to Gibraltar.
Mr Purdon and a group of men ended up hiding in a cellar, waiting for night to return.
But it did not take long before a door was flung open and they were greeted by German soldiers with machine-guns and stick grenades.
His colonel knew it was over.
"Right, we've done what we came for," Mr Purdon remembers the colonel telling his men, and then putting his pipe in his mouth as they were escorted out.
"If I'd been them (the Germans), I'd have chucked those grenades," reckons Mr Purdon.
One of his fellow veterans recalls the Germans even patting some British soldiers on the back in admiration of their bravery.
But still the mission looked like it might not have succeeded.
Hours after it was supposed to have destroyed the gates, the bomb on Campbeltown had not blown. The Germans, not realising explosives were on board, had begun to tour the ship.
Finally, just before midday, the massive bomb finally detonated.
"There was an almighty noise," recalled Mr Purdon, by then a prisoner-of-war.
"We cheered like anything," he said.
The dock would be out of action until after the war. The Tirpitz never ventured into the Atlantic and was later sunk off the coast of Norway.
Mr Purdon was taken first to one PoW camp. When he escaped, he was then sent to Colditz, where he spent the rest of the war.
The raid was a success but it came at a price.
That was clear from a ceremony on Wednesday at what is known as the "English cemetery", a few miles along the coast from the scene of the raid in what is now a quiet suburban street.
Small wooden crosses were placed on the many graves of those who never returned.
Nearly 170 British servicemen were killed. In all five Victoria Crosses were awarded for the operation and more honours were awarded in a shorter time than for any other battle during the war.
"Because it was a crazy idea, it was likely to succeed," says Bob Montgomery, who was in charge of the commando demolition teams.
On a bright sunny afternoon he explained to me: "It's something we British do. It may not seem part of our character. But it is up our sleeve."