When scuba divers need to say 'I'm okay' or 'Shark!' to their dive partners, they use hand signals to communicate visually. But sometimes these movements are difficult to see. Now, researchers have constructed a waterproof 'e-glove' that wirelessly transmits hand gestures made underwater to a computer that translates them into messages. The new technology could someday help divers communicate better with each other and with boat crews on the surface.