If you’re ever stranded at sea with nothing but a bag of lemons, it might be helpful to know that most of them float. Apparently it’s because they’re full of pockets of air that make them less dense than water. By that logic, our sparkling juicy water should float pretty well too. It’s a mix of bubbly spring water, lemon juice and lime juice, which is good news if you’re after a buoyancy aid that’s also tasty and refreshing. The bad news is that limes don’t float, so there’s a chance the whole lot will go down hook, lime and sinker. On second thought, it's probably best enjoyed on dry land.