Sunscreen? Check. Beach chair? Check. Waterproof, floatable boom box? Check. Now that’s a possibility with Grace Digital Audio’s Eco Terra, a 100 percent waterproof boombox for iPhone, BlackBerry and MP3 players (or any phone with a 3.5mm audio jack). The orange IPX7-approved audio blaster is fully submersible and floats, so you can even take it out in the water.