Built in 1978, by the Rayco Shipbuilders and Repair Company of Bourg, Louisiana (hull #63) as the Jane S. for the Bright Equipment Corporation of Sea Bright, New Jersey.
In 1990, the tug was acquired by the East Coast Tender Services Incorporated of Sea Bright, New Jersey. Where she was renamed the tug as the Capt. Mark.
In 1996, she was acquired by the Great Lakes Dredge and Dock Company of Oak Brook, Illinois. Where she was renamed as the Douglas B. Mackie.
In 2003, the tug was acquired by the Lake Michigan Contractors Company of Holland, Michigan. Where she was renamed as the Shirley Joy.
In 2003, she was acquired by Subaqueous Services Incorporated of Jacksonville, Florida. Where the tug retained her name.
In 2006, the tug was acquired by the Milton Point Investments Company of Rye, New York. Where the tug was renamed as the James William.
In 2007, the tug was acquired by Harley Marine Services Incorporated of Seattle, Washington. Where she was renamed as the HMS Liberty.
Originally powered by two, Detroit Diesel 149 diesel engines. Tug was repowered in 2009 with Cummins QSK 38 diesel engines. With Twin Disc 540 reduction gears, at a ratio of 7:1. Turning two, 79(in) by 76(in), four bladed, fixed pitch, stainless steel propellers. For a rated 2,400 horsepower.
Her electrical service is provided by two, 50kW Onan generator sets. The tug's capacities are 20,000 gallons of fuel, and 5,000 gallons of water. Her towing gear consists of a Smatco 44 single drum towing winch.