The War Zone – The Naval Postgraduate School (NPS) has helped develop an autonomous underwater float that can monitor and transmit oceanographic and underwater acoustic data near-indefinitely, and in near real-time. Known as the Persistent Smart Acoustic Profiler (PSAP) Voyager, it is powered by temperature differences in the ocean, providing enough energy to run its instrumentation for far longer than other non-wired undersea eavesdropping hydrophones currently in operation. Such an innovation could have big implications for undersea sensing and detection.