The ocean is a Turing machine, the sand is its tape; the water reads the marks in the sand and sometimes erases them and sometimes carves new ones with tiny currents that are themselves a response to the marks. Plodding through the surf, Waterhouse strikes deep craters in the wet sand that are read by the ocean. Eventually the ocean erases them, but in the process its state has been changed, the pattern of its swirls has been altered. Waterhouse imagines that the disturbance might somehow propagate across the Pacific and into some super-secret Nipponese surveillance device made of bamboo tubes and chrysanthemum leaves; Nip listeners would know that Waterhouse had walked that way. In turn, the water swirling around Waterhouse’s feet carries information about Nip propeller design and the deployment of their fleets – if only he had the wit to read it. The chaos of the waves, gravid with encrypted data, mocks him.