BRUNSWICK, Ga. AP – Environmentalists asked a federal judge Thursday to decide whether the Navy must halt plans to build a $100 million offshore training range because of potential threats to endangered right whales.

The Navy wants to install an undersea array of cables and sensors for training warships, submarines and aircraft about 50 miles off the Atlantic coast of southern Georgia and northern Florida. Environmentalists have sued to block the project, saying it’s too close to waters where right whales migrate near shore each winter to birth their calves.