Underwater communication has been a major technological issue since the start of autonomous (scuba) divers and deep-sea vehicles (DSVs). In recent years, wide-area sensor networks have enabled the close monitoring of environmental and extreme weather conditions, as well as emergency alerts in case of tsunamis and volcanic ash clouds. However, these networks usually require long-range communications and expensive satellite uplinks, in order to send data to a base station, since a fully-wired grid of hundreds of sensors over areas of thousands of square km is not a feasible solution.

Sea water has very different signal propagation properties than open air. The major problem with electro-magnetic (RF) signals under water is that they fade very quickly with distance. A typical WiFi hotspot of some 100-200 mW transmission power becomes 10-20 times weaker, which practically makes it no more than a Bluetooth-like ultra-shortrange headset.