There’s one shark swimming in the sea that’ll smell blood, but won’t act. One shark that’ll sense a vulnerable human swimmer’s legs in its midst, but won’t attack. Won’t bite. Won’t maim. Won’t kill.

Why? Because it’s not really a shark at all.

It’s a robot — a drone — and it’s nicknamed “GhostSwimmer” and it belongs to the United States Navy.

It’s an unmanned underwater vehicle (UUV), and it lives at Joint Expeditionary Base Little Creek – Fort Story (JEBLC-FS) in Virginia Beach, Virginia (the video above is from 2014).

It was created and built by the chief of naval operations’ Rapid Innovation Cell (CRIC) project, Silent NEMO.

It can gauge a number of different factors underwater, and relay the information to sailors and divers in the area (like temperature, wakes, tides, harsh weather, etc. BUT it also has another function (duh).

Spying.

Why else would it look so much like a real razor-toothed scaly swimming monster (it’s five feet long and about 100 pounds)?

This from Dutchsinse:

“It swims just like a fish does by oscillating its tail fin back and forth,” said Rufo. “The unit is a combination of unmanned systems engineering and unique propulsion and control capabilities.”

Its bio-mimicry provides additional security during low visibility intelligence, surveillance and reconnaissance (ISR) missions and friendly hull inspections, while quieter than propeller driven craft of the same size, according to Navy Warfare Development Command (NWDC).

The robot is capable of operating autonomously for extended periods of time due to its long-lasting battery, but it can also be controlled via laptop with a 500-foot tether. The tether is long enough to transmit information while inspecting a ship’s hull, for example, but if operating independently (without a tether) the robot will have to periodically be brought to the surface to download its data.

“This project and others that we are working on at the CRIC are important because we are harnessing the brainpower and talents of junior Sailors,” said Capt. Jim Loper, department head for Concepts and Innovation, NWDC. “The opportunity for a young Sailor who has a good idea to get that idea heard, and to get it turned into action, is greater [now] than any other time in our Navy’s history.”

But, this summer, if you do come across a shape in the water that looks like GhostSwimmer? It’s a real shark. So, save yourself.