Built in 1970, by the J.M. Martinac Shipbuilding Corporation of Tacoma, Washington (hull #182) as the Seneca for Crowley Marine Services Incorporated of San Francisco, California.
She was the first Seneca class tug constructed for Crowley Marine Services Incorporated.
In 2012, the tug was acquired by the Island Tug and Barge Company of Seattle, Washington. Where the tug was renamed as the Island Viking.
Powered by two, eight cylinder, EMD 8-645-E5 diesel engines. Turning two, cast steel, fixed pitch propellers. She is a twin screw tug, rated at 3,000 horsepower.
Her electrical service is provided by two, 115kW generator sets. The tug's capacities are 51,777 gallons fuel.