Built in 1947, by the Dravo Corporation of Pittsburgh, Pennsylvania (hull #2470) as the Pennsylvania for the Pennsylvania Railroad Company of Philadelphia, Pennsylvania.

In 1969, the tug was acquired by Cardinal Carriers Incorporated of Louisville, Kentucky. Where she was renamed as the Bluebird.

In 1973, Cardinal Carriers Incorporated renamed the tug as the Utah.

In 1978, Cardinal Carriers Incorporated renamed the tug as the Kathryn.

In 1988, the tug was acquired by West Indies Transportation Company Incorporated of St. Thomas, Virgin Islands. Where she was converted to ship docking tug and was renamed as the Witassist II.

In 1997, the tug was acquired by Puerto Rico Operations Incorporated of Old San Juan, Puerto Rico. Where the tug retained her name.

In 2002, the tug was acquired by American Tugs Incorporated of San Juan, Puerto Rico. Where she was renamed as the Proassist II.

In 2010, she was phased out of active service and was "laid up" at La Mareas, Puerto Rico.

Powered by two, Fairbanks Morse 38 D 8 diesel engines. With Lufkin reverse / reduction gears at a 2.5:1. She was a twin screw tug, rated at 4,200 horsepower.

Her electrical service was provided by two, 30kW, Delco generator sets. Driven by two, Detriot Diesel 6-71 diesel engines.