Aquabike
Aquabike (aka Aquavelo) is an endurance sport composed of swimming and cycling stages. In 2006, USA Triathlon sanctioned about 30 Aquabike events with many taking place at the 70.3 km events. It consists of swimming and biking, usually taking place simultaneously with and on the same outdoor course as a triathlon competition. The running stage is eliminated so that people with joint problems prohibiting them from running such distances can still compete.
The Aquabike Series was a pilot program in 2005 in which athletes competed in the swimming and cycling portions of a half or ultra distance triathlon, but did not do the run. As of 2011, at least 29 states were holding Aquabike events.