At 80, shipyard skipper to step back after Zumwalt trials

The 80-year-old river pilot and sea captain extended his contract at Bath Iron Works to ensure he could pilot the 610-foot warship safely through three sea trials.

The river's tricky currents and twisting turns leave little margin for error when steering big warships coming and going from the shipyard.

For the Zumwalt, care was required to ensure that the largest destroyer ever built for the U.S. Navy didn't drift sideways, he said, and calculations had to be precise to ensure the sonar and propellers didn't nick the river bottom.

Because the ship displaces more water when it moves, the 2 feet of underwater clearance at several locations on the river actually shrunk to only 12 to 18 inches, he said.

If that isn't tricky enough, visibility was restricted.

Because of the ship's design, Walker couldn't see the water directly alongside its sloping hull when docking and undocking.