I use SwimSafe for open water training and racing. I’m training for my 4th Ironman and I like that it is available in case there is a problem. I prefer the waist model as opposed to those that are around the thigh. I’ve never had to "use" it during a race, but it’s there if I need it. I wish Ironman would require SwimSafe at their events as there have been a lot of people who have drowned who may have benefited from it.