Since the 1970s the US Navy had started to train dolphins and sea lions to protect submarine pens and to locate hidden mines. They were deployed in the US on both coasts and also overseas to counter enemy divers. Dolphins were photographed during ODS and the US Navy maintains 80 dolphins (Alpha Blues) plus 40 sea lions. But after decades, improvements with UUV (Unmanned Underwater Vehicles), the new General Dynamics/Bluefin Robotics Knifefish has been designed to replace the "biologicals". Knifefish is a torpedo-like UUV that can scan the seas electronically and optically looking for hidden mines and other naval threats. it can patrol for long periods of time and can be massed-produced without all the support needs of the naval animals and transport issues overseas. Knifefish is in the water now testing, but it won't be until 2017 until they reach full IOC in numbers.

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