An endurance athlete who gave up triathlons because they were "boring" is set to attempt a gruelling challenge never achieved before.

Mark Bayliss, 35, of Longsdon Way, Caterham, will take on the Arch to Arc triathlon, a 289 mile slog, including a run from London to Dover, swimming the channel, then cycling from Calais to Paris, this week.

The brutal event has only been completed by 10 previous competitors, but not content with this, Mr Bayliss will take on the swim without a wetsuit, the first to attempt this feat as part of the Arch to Arc.

He said: "There are few things in life you can do where you can honestly say ‘No-one else has done this’. I don’t want to take on challenges where there isn’t a risk I won’t be able to complete it."

By shunning the wetsuit, he will have to cope with the severe cold of the sea as well as reduced buoyancy.

A company director of Croydon based delivery company Wings Transport, Mr Bayliss took up triathlons aged just 11 but after a number of years found the event no longer fed his need to push himself.

He said: "I got bored. The motivation just became to go quicker, and so I began looking for something new."

In 2007 Mr Bayliss, who married last year, successfully swam the channel, and last year he completed the Marathon des Sables, a 251km run through the Sahara desert.

Hoping to set out today (Wednesday September 5) at 6am Mr Bayliss will run the 87 miles to the coast in about 20 hours before taking a 15 to 20 hour rest to recuperate.

He will then swim the channel in around 12 hours, rest for a few hours and finally take on the 181 mile cycle in another 12 hours.

The record time to complete the Arch to Arc is 81 hours.

He said: "For the moment I’m just focussing on finishing. If the record is on the cards then I’ll have another think but I don’t want to push myself too hard early on and jeopardise the whole challenge.

"The key is in the rests - I am following the schedule others have done. One day someone will blow the record out of the water by massively cutting down on the rests, but that man is not me."

Mr Bayliss will be completing the challenge for SportsAid, which supports up and coming athletes.

To sponsor him visit uk.virginmoneygiving.com/MarkBayliss.