Built in 1970, by McDermott Shipyard Incorporated of Morgan City, Louisiana (hull #167) as the Ocean Star for the L and L Marine Service Incorporated of St. Louis, Missouri. A subsidiary of the Apex Oil Company of St. Louis, Missouri.
In 1975, she was acquired by the Foss Maritime Company of Seattle, Washington. Where she was renamed the Agnes Foss.
In 2004, the tug was acquired by the SeaCoast Transportation Company of Seattle, Washington. Where she was renamed as the Pacific Raven.
In 2007, Sea Coast Transportation was acquired by the K-Sea Transportation Partnership Incorporated of East Brunswick, New Jersey. Where the tug retained her name.
In 2011, the K-Sea Transportation Partnership Incorporated was acquired by the Kirby Corporation of Channelview, Texas. Where the tug retained her name.
In 2017, she was phased out of active service. And, was "laid up."
In 2018, the tug was acquired by the Curtin Maritime Company of Long Beach, California. Where she was renamed as the Shirley C.
Powered by two, twelve cylinder, EMD diesel engines. Turning two, cast steel, fixed pitch propellers. She was a twin screw tug, rated at 3,000 horsepower.
Her electrical service was provided by two, 98kW generator sets. The tug's capacities are 91,908 gallons of fuel.
(Kyle Stubbs, Captain Russell Shrewsbury)