Built in 1949, by the Marine Construction Company Incorporated of Seattle, Washington as the Sea Horse for the Pacific Tow Boat Company of Everett, Washington.
In 1969, the Pacific Tow Boat Company was acquired as a subsidy of the Dillingham Corporation of Honolulu, Hawaii. Operations of the two companies placed under the management of the Foss Maritime Company of Seattle, Washington. Where the tug retained her name.
She was later acquired the by Cook Inlet Tug and Barge Company of Anchorage, Alaska. A division of the Anderson Tug and Barge Company of Anchorage, Alaska. Where she was renamed to Junior.
In 2013, the Cook Inlet Tug and Barge Company was acquired by Saltchuk Resources of Seattle, Washington. And was established as an independent subsidiary of Foss Marine Holdings of Seattle, Washington.
Powered by two, Caterpillar 3412 diesel engines. She is a twin screw tug, rated at 1,300 horsepower.