The HMS Triumph, the manned British submarine that was lost more than 80 years ago, may finally have been located. 

Divers are adamant they have discovered the lost sub in the Aegean Sea at a depth of 666 feet (203 metres). 

The 275-foot ship was operating off the coast of Greece when it vanished without a trace under mysterious circumstances in January 1942.

Bodies of 64 men who were aboard at the time – all British personnel who had won 36 medals for bravery between them – are thought to still be within the submarine. 

Stunning video footage shows the newly-discovered wreck, yet to be confirmed as HMS Triumph, tens of kilometres off the coast of Cape Sounion. 

Distinctive features on the sub’s hull and the location of the wreck have led divers to conclude it’s ‘unequivocally’ Triumph, although further assessments are ‘ongoing’. 

Veteran Greek diver Kostas Thoktaridis, who first learned about the story of HMS Triumph back in 1998, called this self-funded mission ‘the hardest I’ve ever undertaken in my life’. 

Along with colleagues, he found the sub using a remotely operated vehicle (ROV) with sonar, which makes use of sound waves to ‘see’ through water and detect underwater objects. 

Equipped with cameras, the ROV then filmed haunting footage of the wreck, capturing details such as the rusted stern, top hatch and manholes. 

Even though it’s been more than 80 years since it sank, the wreck is well preserved, albeit covered with barnacles and other marine organisms. 

Thoktaridis and colleagues have already located the wrecks of four submarines in Greek waters, including HMS Perseus in 1997. 

‘The history of the submarine Triumph is multidimensional and unique in maritime history, and is inseparable to national resistance and the secret services that acted in the dark days of occupation,’ Thoktaridis said. 

‘The wreck site is treated with respect as it is a wet grave of 64 people.’ 

The exact location will not be disclosed, due to Greek archaeology laws that aim to protect shipwrecks from disturbance. 

There are lowered visors and closed manholes, which indicate that the sub was on a deep dive in its last moments, according to Thoktaridis. 

In the submarine’s tower, divers also spotted the wooden steering wheel, compass, and four-inch cannon, which is slightly raised upwards. 

HMS Triumph, a T-class submarine of the Royal Navy, was built by British engineering firm Vickers at Barrow-in-Furness and launched in 1938. 

Triumph had a successful career during the early years of World War II, sinking several enemy ships in the Mediterranean from early 1941. 

In December that year, the submarine was tasked with landing a party of British agents on the Greek island of Antiparos.

Although the mission was successful, HMS Triumph was due to pick up the agents on January 9, 1942 – but she failed to arrive. 

Exact circumstances surrounding her sinking and the fate of those men on board could be lost to history.

However, Thoktaridis believes the cause of the sinking appears to have been a ‘high-power explosion’ in the anterior section, possibly due to a mine or torpedo. 

Nearby to the wreck the team also found British Mk VIII torpedoes of the same type with those carried by HMS Triumph. 

‘This fact leads us to believe that the Triumph fired more than one torpedo during its latest assault,’ Thoktaridis said. 

Gav Don, a former Royal Navy officer who has himself spent many years trying to locate the sub, told MailOnline that he feels a mix of both ‘happy and sad’ now it’s been located. 

Mr Don’s uncle, gunnery officer Robert Douglas-Don, was one of the 64 men on board the ship and was just 23 when he lost his life.  

Along with other relatives, Mr Don will be part of a trip to the coordinates of the site, which will hold a service and a toast for their loved ones. 

‘This quest has been part of my life for a very long time,’ Mr Don told MailOnline.

‘I first started wondering where Triumph was when I was about 10, so there’s always been a hole.

‘Though we should regret Triumph’s loss and mourn her men, we should also celebrate her career and her successes.’ 

Another one of the relatives of the 64 men who died on HMS Triumph is Karen Wenborn, based in south Wales, who called the discovery ‘truly amazing’. 

Mrs Wenborn’s grandad Harry Cross, an able seaman aboard the sub, sent a letter to his parents shortly before he died at the age of 32. 

‘One of his children, my Auntie Brenda, is still alive to see it happen,’ Mrs Wenborn told MailOnline. 

‘Harry was a true mariner and volunteered to be on Triumph. He had been torpedoed once and survived and was given the option to change to a ship but he opted to go back into a sub. 

‘He sent a letter to his parents just before he Triumph was lost to say how well he was and he’d see them soon. My dad was just seven when Harry died.’ 

The Ministry of Defence will now liaise with partners involved to seek additional information on the submarine.

Officially authenticating the identity of the wreck is the next step, according to the Royal Navy, although Mr Don said it is ‘unequivocally’ that of Triumph.  

‘Although HMS Triumph was known to be operating in the area at that time, further assessment work is ongoing to clarify the wreck’s identity,’ a Royal Navy spokesperson told MailOnline. 

‘Irrespective of this, it is the last resting place of personnel onboard who died, and we request that the vessel is left undisturbed.’