I'm getting ready to do a Butterfly challenge in which I swim 50 lengths of fly (SCY). I've swum a thousand yards in a single workout with no problem, so the distance itself isn't a big challenge for me, but I'm going to try and do the entire 1,250 yard distance without stopping. This got me thinking maybe I could take on a bigger challenge out in the open water. I have heard there are certain rules for an open water endurance swim to officially count, but I'm having trouble finding anything specific about exactly what those rules are and how to ensure I'm following them. Does anyone have any information on that?