Went from 1.5 mph to more than 3 mph which many marathoners say was deeply suspicious. >> you know, it's just pure math. i can't imagine. i can see from a lay public who doesn't understand currents but people from the marathon swimming world, you have to know you're in the gulf stream, you can pick up the navigational charts and any website available that shows these things and sometimes you're going with no current whatsoever, so then of course, you're just going the exact speed you swim. other times you're going north against an eastern faced current and now you're going with a little bit of...