A 13-MILE kayak, one mile swim, 16-mile cycle ride and five-mile run would be the ultimate test of endurance for the fittest of sports enthusiasts.

Combine that with the unpredictable waters of The Wash and Chapel St Leonards men Toni Schofield and Tom Wann have set themselves the challenge of a lifetime.

The pair are in training for a record-breaking "quadrathon" attempt, which they hope will raise significant funds for the National Hereditary Breast Cancer Helpline.

On June 25, Toni and Tom will set off from Hunstanton at 9am to row across The Wash to Skegness.

This will be followed by a one-mile swim from Skegness Boathouse, a 16-mile cycle ride and finish with a five-mile run across the beach to Chapel St Leonards bell tower.

Toni, 47, said: "We are expecting to meet problems out there without a shadow of a doubt. The tide changes every hour and it is one of the most dangerous stretches of water in the world, that's why no one has done this before.

"The under current causes the sand banks to be constantly moving so we have to make sure the journey is timed correctly as we will only have a short window of opportunity."

The pair will navigate using hand held GPS to keep them on course and will have to contend with a water temperature of between 10 and 12 centigrade.

They have sought the help of local coastguards and RNLI who have provided support and advice.

Toni added: "We are also aware of an additional menace as a number of sharks have been spotted off the Lincolnshire coast, plus jelly fish and poisonous weever fish."

Their chosen charity was set up by Wendy Watson who in 1993 took the brave decision to have a double mastectomy to prevent her getting breast cancer, something which ran in her family.

Wendy set up the helpline in 1996 and after her daughter Becky tested positive for the BRCA1 (mutated breast cancer gene) she too had both her breasts removed at the age of 18.

Seeing her story in a national magazine inspired Toni and Tom to fundraise for them.

They are now undertaking an intense training programme of around four hours a day, and doing 9,500 sit-ups and 1,500 press-ups a week.

No strangers to strong man events, Tom, 29, has previously completed the Three Peaks Challenge and the Kilamanjaro challenge and both men will be taking part in a cycle ride from Skegness to Liverpool and back and an Iron Man competition later in the year.

Rich and Iris Jarvis from Millers in Chapel St Leonards will be providing light refreshments after the event as well as accepting donations and raffle prizes in the run-up to the day.

To sponsor Toni and Tom visit www.justgiving.com/ Helpline-Quadathon