Just as a duathlon is a modified triathlon for those who can't (or won't) swim, an aquathlon (see the Wikipedia entry) is an event for those who forgot that they needed a bike! Unlike a duathlon which, traditionally, has three stages (run, bike, run) an aquathlon often has just two; swim and run. The order is not rigid, although it's a lot easier to swim first and then run. The ITU, triathlon's governing body which looks after duathlon and aquathlon as well, runs its World Championships as a run, swim, run with the second run generally being half the distance of the first (although this is somewhat at odds with the ITU's own rules which state 2.5k, 1k, 2.5k).

Another variation of the sport, and run under a completely different governing body (it's considered part of Pentathlon...), is Biathle. This is also a run, swim and run combination and has a series of events around the world and a World Championship. See the links below for further information.

Aquathlons take place all year round and range from as short as a 500m pool swim and a 5k run through to 2k (or more) open water swims and 10k runs.

A variation on the theme is aquabike where you swim and then bike but the discipline has no formal status and these are just races put on as part of an event where the organiser is trying to offer as much choice as possible.

Information resources