Starting at 2.30pm and finishing at Tibbie Shiels Inn, competitors will first take on a 1,500 metre swim in the famous loch (wet suits compulsory) before attempting a daunting 30km mountain bike ride in the surrounding hills.

The last leg will be a 10km run across equally challenging terrain.

A half-distance event aimed at novices and newcomers will start at 3.30pm.

“We’ve really come a long way in seven years,” said a spokesperson for the organisers. “Around a hundred competitors took part in the first Durty Triathlon and it has gone from strength to strength, reflecting a huge surge in interest in the sport.

“It has remained true to its amateur ethos with people of all ages and abilities welcome.” The race, which gets its misspelt name from some notorious boggy stretches on the bike and running course, is expected to see hundreds of spectators and supporters descend on the well-appointed camping and caravan site next to the hotel which has laid on live music on Saturday evening.

It will be provided by the Border Boogie Band who will start rocking following the prize-giving ceremony at around 7.30pm.

Entries for the Durty Triathlon close at the end of today (Wednesday). Athletes can register online at www.entrycentral.com