Swimming depends on a few things: the viscosity of the liquid, the relative density of the liquid to yourself, and how out of shape you’ve let yourself get. 😉 My family went to the Bahamas after Christmas, and it’s amazing how much easier it is to stay afloat in the ocean as opposed to the lakes we’ve got up here in Minnesota. Gives me boundless admiration for those who’ve survived falling into Lake Superior, which is very cold, big enough to have ocean-like swells, and, of course, freshwater. So salinity is a big deal. But what if we changed another variable? Say, the gravity?
XKCD What If? was asked this question, and specifically, what would it be like on the Moon? The answer: it would be *awesome*. Seriously, go read it and dream wonderful dreams tonight. 😉 A lot of it would be the same, but you could totally leap like a dolphin.