Silver knew that radio waves couldn’t travel through salt water, not at this pressure and temperature. However, the Jym suits carried something called a Gertrude, an acoustical sea phone. The five of them could talk, and it was supposed to be impossible to tell the scrambled sonic signals from natural biological background noise. Or, at least, that was the theory. The darkness compounded with silence was intolerable, so the risk was worth it. Besides, she had other uses for her radio.