I’ve got good news for all you would-be wild swimmers. If you’re looking to join this newfangled fad of swimming outdoors, you’re in luck. Take a second, look around you, your planet is… blue. You’re surrounded by potential playgrounds for you to stretch your limbs, dunk your head and start ploughing through the water. Great bodies and arms of water flow, swell and roll everywhere. If you were stranded on Mars you’d be flat-out on your belly, pawing through red, sun-baked dust and rubble, but, seen as you’re here in the oceanic clutches of Earth, you’re going to have a hard time keeping dry – you might as well make the most of it, right?