WHAT better way to celebrate turning 40 than by swimming the length of Lake Windermere?
But it is all in a good cause for Marcus Caton, who is hoping to raise more than £2,000 for the Anthony Nolan blood cancer charity and bone marrow register, which is also celebrating its 40th year.
He will head to the Lake District to make his attempt on September 7 and is keeping his fingers crossed for good weather.
Mr Caton said: "Something like the warm, sunny weather we have been having recently would be great.
"But I will be wearing a wetsuit in any case, because I don't expect the water temperature to be much more than 17C."
Earlier this year, Mr Caton, of Wyaston, approached neighbour Allen Forsyth, who is a member of the Anthony Nolan Ashbourne Friends, about being one of just 100 people who will take part in the Windermere Wild Swim, from Fell Foot Park to Low Wray.
Mr Caton, who grew up in New South Wales, Australia, said: "After I made inquiries, I then discovered that my wife, Hannah, who comes from Thorpe originally, had entered me for the event as a present."
Since then he has been busy training, although he is no stranger to sport generally, spending much of the year as national panel referee for the Rugby Football Union.
He also swims regularly, especially with his three small children, aged six, four and two, and cycling.
Mr Caton, who is head of sixth form at Long Eaton School, said: "Growing up and living in Australia for over 30 years, I have always had an affinity with the water, but since marrying a country lass and now living 100 miles from the sea in the hills of the Peak District, it is time to return to the open water."
He has already raised more than £500 and is hoping to pass his target of £2,000.
Mr Caton said: "I know that Allen is a tireless worker for the charity and it seemed quite natural to suggest I have a go at this challenge and raise money at the same time.
"I have been putting in extra training sessions at Ashbourne Leisure Centre and also in open water at Hilton, Barton Marina and in Wales, where we occasionally holiday.
"I am hoping that one day my children will be able to accompany me on a similar sort of swim to this one."
Mr Forsyth is delighted Mr Caton has decided to take part in the Windermere swimming challenge.
He said: "When Marcus told me what he wanted to do, I was amazed but also very pleased. I know he has been training very hard and that he achieved seven miles recently and is extending that distance, weekly. I wish him all the best in his attempt."
Anyone wishing to make a donation to Mr Caton should visit www.justgiving.com/macswimswindi/.