The State Department said it is "working closely" with Mr. Ballard in what will be a sophisticated sonar search.

WSJ: Amelia Earhart: New Try to Solve Old Mystery

Several Coast Guard cutters, the Honduran Navy and FBI dive teams then used side-sonar equipment to search for the sunken submarine-like vessel, which was located on July 26.

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It was discovered by a survey ship with sonar equipment involved in the search for the Weymouth-based boat.

BBC: The Purbeck Isle

Specialist sonar equipment will once again be used to search the mouth of the River Ely in Cardiff Bay.

BBC: Ben Thompson