Built in 1974, by Main Iron Works of Houma, Louisiana (hull #279) as the Cecile B. for Notly J. Theriot Offshore Incorporated of Golden Meadow, Louisiana.
In 1984, the tug was acquired by International Marine Incorporated of New Orleans, Louisiana. Where she was renamed as the Cecile.
In 1989, she was acquired by United Marine Tugs Incorporated of Seattle, Washington. Where the tug was renamed as the Cecile B.
In 1992, the tug was acquired by Victory Marine Incorporated of Seattle, Washington. Where she was renamed as the Sea Valiant.
In 1993, she was acquired by Crowley Marine Services Incorporated of San Francisco, California. Where she was renamed as the Pacific Victory.
In 2004, the tug was then acquired by the Sirius Maritime Company of Seattle, Washington. A division of Hawaiian InterIsland Towing Incorporated of Honolulu, Hawaii. Where she was renamed as the Sirius.
In 2007, the Sirius Maritime Company was acquired by the K-Sea Transportation Partnership of East Brunswick, New Jersey. Where the tug retained her name.
In 2011, the K-Sea Transportation Partnership was acquired by the Kirby Corporation of Channelview, Texas. Where the tug retained her name.
Powered by two, sixteen cylinder, EMD 16-645-E5 diesel engines. Turning two, cast steel, fixed pitch propellers. She is a twin screw tug, rated at 5,750 horsepower.
Her electrical service is provided by two 99kW generator sets. The tug's capacities are 172,000 gallons of fuel.