Built in 1982, by the Marinette Marine Corporation of Marinette, Wisconsin (hull #8721) as the April T. Beker for the Beker Transportation Company of Greenwich, Connecticut.
She was paired with self-unloading barge the Erol Y. Beker which was constructed in 1982 at Bay Shipbuilding of Sturgeon Bay, Wisconsin alongside of the tug.
In 1985, unit was acquired by Gulfcoast Transit Company of Tampa, Florida. A subsidiary of the Tampa Electric Company of Tampa, Florida. Where the tug was renamed as the Beverly Anderson and the barge was renamed as the Mary Turner.
In 2002, the Gulfcoast Transit Company became the TECO Ocean Shipping Company of Tampa, Florida. Where the tug retained her name.
In 2007, she was outfitted with Bludworth coupler system and "married" with the barge Mary Turner.
In 2011, the unit was acquired by the Grand River Navigation Company of Traverse City, Michigan. A division of the Rand Logistics Corporation of Jersey City, New Jersey. Where the tug was renamed as the Defiance, and the barge was renamed as the Ashtabula.
Powered by two, EMD 20-645-E7 diesel engines, she is a twin screw tug, rated at 7,200 horsepower.