Built in 1981 by Melancon Fabricators of Lockport, Louisiana (hull #8) as Angel M.
The tug was later acquired by South Coast Incorporated of Ketchikan, Alaska. Where she was renamed as the Maritime.
Later acquired by Forty Niner Transportation Incorporated of Seward, Alaska. Where the tug was renamed as the Petro Spirit.
In 1999, she was acquired by FuelTrans Leasing, LLC of Portland, Oregon, where she was renamed as Northern Spirit.
In 2004 the tug's sale was brokered by Marcon International to Island Tug and Barge of Seattle, Washington, where she was renamed as Island Spirit.
In 2016, she was acquired by Hamilton Marine Construction of Anchorage, Alaska, where the tug was renamed as Skookum.
She is powered by two Caterpillar 3512TA diesels connected to Twin Disc 4.60:1 reduction gears driving twin fixed pitch propellors in kort nozzles. She produces 2,560 horsepower providing 30 tons of bollard pull.
The tug is fitted with a Smatco 55DSL 170/GM4-71 single drum towing winch suppled with 2,250(ft) of 1.75(in) wire.