Built in 1998, by Nichols Brothers Boatbuilders of Freeland, Washington (hull #128) as the Captain for Crowley Marine Services Incorporated of San Francisco, California.
Designed by Naval Architects, Guido Perla and Associates of Seattle, Washington. She was the second Harbor class tractor tug designed, and constructed Crowley Marine Services Incorporated.
The Harbor class tugs were designed specifically, for ship assist, and escort duties. She features a hydrofoil shaped skeg, that provides for greatly improved steering, control, and seakeeping. It allows the vessel to run at high speeds in the skeg-first direction. In addition the hydrodynamics of the hull result in increased tons of steering, and braking force. Which are available to assist, or control a vessel at higher speeds.
In 1998, Crowley Marine Services, renamed the tug as the Admiral.
Powered by two, Caterpillar 3516-B diesel engines. With two, Voith-Schneider cycloidal drives. The tug is rated at 4,800 horsepower.