By Aaron Gregg, Reporter Washington Post

More than a decade after airborne drones took flight over battlefields, the world’s biggest defense manufacturers are eyeing a new market below the ocean’s surface.

The Navy recently opened up a competition for unmanned submarines that can navigate autonomously. Chicago-based Boeing has taken an early lead in the fledgling market: The company has developed a 51-foot-long vessel called the Echo Voyager to compete for the contract, and last year it bought a company called Liquid Robotics that focuses on smaller unmanned subs.

Bethesda-based competitor Lockheed Martin is also competing for the contract, a company spokeswoman said Thursday, and it, too, is now ramping up its efforts by investing in another company specializing in the autonomous watercraft.

The company’s technology investment unit, Lockheed Martin Ventures, announced Friday that it is backing a San Diego-based company called Ocean Aero, which makes various classes of seafaring drones, termed unmanned underwater vehicles, or UUV’s. The size and terms of the transaction were not disclosed, but the venture unit typically makes investments of between $1 million and $5 million.

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