John Bevan, a former Royal Navy diver, died on February 3 after a long battle with cancer.
The founder of both the Historical Diving Society and the Diving Museum in Stokes Bay, John was also an author and much-loved by the community.
Terry Rhodes, who helps organise the Heritage Open Days in Gosport, says his death is a huge loss for the town.
She said: ‘I was looking through all the old photographs of John and realised there isn't a single picture where he’s not smiling.
‘He was a lovely gentleman who knew how to have a good laugh and was well-liked by everybody.
‘It's hard to replace somebody like that – he was just so kind and had a wonderful sense of humour.’
When it came to diving John was a recognised world-beater, even stumping US navy divers with his incredible feat.
In March 1970, he and fellow Royal Naval Scientific Service diver, Peter Sharphouse, took a world record simulated dive of 457m (1,500ft), breaking through the helium barrier.
The pair spent a gruelling 10 hours in an experimental compression chamber, going 90m deeper than what was considered to be possible at the time.
John founded the Historical Diving Society in 1990, which has grown ever since.
When he moved to Gosport 15 years ago, he and Kevin Casey became close friends, establishing the Diving Museum at No2 Battery.
Kevin, now a town councillor, said: ‘It’s very sad, I’m really going to miss the guy.
‘We would always go to the pub for a few beers together, or I’d cycle over to his house for a few drinks – we were very good friends.
‘If it wasn’t for John, Gosport would know nothing about its rich diving history. He had so much knowledge of diving and his research has had a massive impact on the town.’
John's funeral will be held on February 21 at Holy Trinity Church, Trinity Green, Gosport.
The service will start at 11.30am.