What is marathon swimming?
A marathon swim is a continuous swim of at least 10km, using only a textile swimsuit, non-neoprene cap, goggles, and grease. This distance was chosen for its equivalence in time-to-completion to a 26.2-mile marathon run. Alternative definitions suggest a minimum distance of 10 miles or 20km.
The basic rules of marathon swimming have stood for nearly 140 years:
- Nothing may be used or worn that aids speed, buoyancy, heat retention, or endurance (e.g., wetsuits, neoprene caps, gloves, paddles, fins, etc.).
- No physical contact with support craft or personnel during the swim.
- The swimmer must start and finish on dry land. When safely accessible dry land is not available, a rock or sheer cliff face with no seawater beyond will suffice.
http://www.loneswimmer.com The World's Most Popular Open Water Swimming Blog