What is being claimed as the first ever scuba relay crossing of the Channel is being planned for this Friday.
Two Navy divers, two journalists, an IT manager, a shop owner and a cancer survivor are making the attempt to raise money for male cancer charity Orchid.
The charity's founder and president Colin Osborne will be among the seven who take part in the underway relay.
"Whilst it will be cold, dangerous and require a huge amount of organisation, we are not just looking to achieve a world record," he said.
"We are looking to help fight the battle against male cancers as it is far from won.
"2006 is my 10th year in remission. This is not a day I thought I'd ever see when I was told I had three months to live 10 years ago.
"The first fundraising event I ever undertook for Orchid was a sponsored dive in the lake at Ilford Golf Club to see how many golf balls I could retrieve. It seemed a natural progression to celebrate our 10th Anniversary with a sub aqua fundraising event.
"We are aiming to begin on Friday but this depends on weather conditions. We have an eight-day window of neap tides between August 1 and 8. We will scuba underwater across to Cap Gris Nez, France leaving from Shakespeare Beach, Dover.
"It could take up to 24 hours with the seven divers taking turns to swim at a depth of 10 metres underwater for half an hour each. Each diver will have radio contact with the support boat but will in effect dive alone."
