A:Answer I had all manner of sarcastic answers, but thought I'd tune it down. They are water resistant to the IPX7 standards for time and depth, and Jaybird calls them Earthproof. To them that means they are sweat and waterproof (with a few caveats). As to swimming with them in your ears; assuming you have a water tight seal, then the buds could produce functional sound, but if you have any water in your ear or the buds, the natural incompatibility between water and sound would come into play, and render them useless in water.