This means that the battery is discharged down to 10.5 volts over a 20 hour period while the total actual amp-hours that it supplies are measured. Sometimes ratings at the 6 hour rate and 100 hour rate are also given for comparison and for different applications.
Pool meets are usually no more than 4 hours, but beach meets last about 7 hours. It depends how many events are in the meet. And then if it is a really big meet (like a tournament kind of) it can last days. Hope that helps.
International Distance Triathlon Swim distance will vary. Distance may range from mile to 1.5k or 800-1700 yards. Olympic Distance Triathlon Swim distance is 1.5k or approximately 1700 yards. Half Iron Distance Triathlon Swim distance is 1.2 miles or approximately 2000 yards. Iron Distance Triathlon Swim distance is 2.4 miles or approximately 4000 yards.