There are two distances to choose from 1.2 mile Lake Swim - 6.5 mile Lakeside Run or 0.6 mile Lake Swim - 3.25 mile Lakeside Run.
One or two complete laps of Alderford's spring fed lake is the first challenge followed by a two or four lap picturesque lakeside run.
Any ability is welcome and everyone receives a prestigious finishers medal.
There are also awards for overall top three male and female as well as first place male and female in 40+, 50+ and 60+ age groups.
Wetsuits are compulsory for the Ultimate Aquathlon and Relay, but not for the Ultimate Half Aquathlon.