Jon Ford will tomorrow brave the 4.3-mile stretch from Ryde Pier, Isle of Wight, to Clarence Pier, Southsea, along with a team of nine of his friends.
The group decided to take on the gruelling Swimming Wight Across challenge to raise £1,000 for Diabetes UK, the Multiple Sclerosis Society and Elizabeth FitzRoy Support.
Jon will be motivated by his 10-year-old son Jack, who was diagnosed with type 1 diabetes when he was just six.
The 40-year-old, of Anmore Road, Denmead, said: 'I do all I can to raise money for Diabetes UK.
'Seeing how challenging life can be for Jack spurs me on to help people with diabetes.
'When I told Jack I was doing the swim he thought it was a fantastic idea. He wanted to do it himself but he does a lot of football so wasn't able to – so I will be doing it for both of us.'
The group of friends, who are all members of the same gym, will set off at 9.30am tomorrow from Ryde Pier. They are expected to arrive at Southsea at about 11.30am.
Despite the arduous conditions of the Solent, Jon says he can't wait to dive in.
He added: 'I am really looking forward to it – I can't wait.
'We have been swimming in the sea to prepare since May, doing two hours a couple of times a week to get our bodies acclimatised.
'I would really appreciate it if as many people as possible could sponsor our efforts generously and come to the start or finish of the event to cheer us on.'
Penny January, fund-raising manager for Diabetes UK in the south east, said: 'Jon and the team's efforts are greatly appreciated by everyone at Diabetes UK and we wish them the best of luck in their challenge.'
fran.duckettpike
@thenews.co.uk