More than 200 shipbuilders, sailors and residents gathered to watch as the futuristic 600-foot (183-meter), 15,000-ton (13,600-metric ton) USS Zumwalt glided past Fort Popham, accompanied by tugboats.
Kelley Campana, a Bath Iron Works employee, said she had goose bumps and tears in her eyes.
"This is pretty exciting. It's a great day to be a shipbuilder and to be an American," she said.
Bath Iron Works will be testing the ship's performance and making tweaks this winter.
More From This Section
The goal is to deliver it to the Navy sometime next year.
The ship has electric propulsion, new radar and sonar, powerful missiles and guns, and a stealthy design to reduce its radar signature.
Advanced automation will allow the warship to operate with a much smaller crew size than current destroyers.
All of that innovation has led to construction delays and a growing price tag.
The Zumwalt, the first of three ships in the class, will cost at least USD 4.4 billion.
The inverse bow juts forward to slice through the waves.
Sharp angles deflect enemy radar signals. Radar and antennas are hidden in a composite deckhouse.
The builder sea trials will answer any questions of seaworthiness for a ship that utilizes a type of hull associated with pre-dreadnought battleships from a century ago.
Critics say the "tumblehome" hull's sloping shape makes it less stable than conventional hulls, but it contributes to the ship's stealth and the Navy is confident in the design.
Eric Wertheim, author and editor of the US Naval Institute's "Guide to Combat Fleets of the World," said there's no question the integration of so many new systems from the electric drive to the tumblehome hull carries some level of risk.
With only three ships, the class of destroyers could become something of a technology demonstration project, he said.