Is that a shark or an unmanned underwater vehicle?

141211-N-KE519-014 VIRGINIA BEACH, Va. (Dec. 11, 2014) The GhostSwimmer vehicle, developed by the Chief of Naval Operations Rapid Innovation Cell project Silent NEMO, undergoes testing at Joint Expeditionary Base Little Creek – Fort Story. Project Silent NEMO is an experiment which explores the possible uses for a biomimetic device developed by the Office of Naval Research. (U.S. Navy photo by Mass Communication Specialist 3rd Class Edward Guttierrez III/Released)

The Navy has tested what it describes as a “tuna-sized” unmanned underwater vehicle (UUV).

“The GhostSwimmer was developed to resemble the shape and mimic the swimming style of a large fish,” according to a Navy announcement. It is five feet long, weighs nearly 100 pounds, and can operate at depths ranging from 10 inches to 300 feet.

“It swims just like a fish does by oscillating its tail fin back and forth,” said Michael Rufo, director of manufacturer Boston Engineering’s Advanced Systems Group. “The unit is a combination of unmanned systems engineering and unique propulsion and control capabilities.”

Mimicking a fish makes ISR missions easier. The GhostSwimmer is also quieter than propeller-driven vessels. It can operate autonomously or via laptop through a 500-foot tether.

The fish-like UUV was demonstrated at Joint Expeditionary Base Little Creek-Fort Story this month, where it has been measuring tides, currents, wakes, and weather conditions.

GhostSwimmer was designed under the Silent NEMO project aimed at designing biomemetic UUVs. Silent NEMO is part of the Chief of Naval Operations’s Rapid Innovation Cell (CRIC) program.