Built in 1973, by McDermott Shipyard of Morgan City, Louisiana (hull #186) as the tug Ocean Wave for L and L Marine Service, Incorporated. A subsidiary of the Apex Oil Company of St. Louis, Missouri.
She was later acquired by the Morania Oil Tanker Corporation of Staten Island, New York. Where she was renamed as the Morania No. 4.
When Penn Maritime merged with the Morania Oil Tanker Corporation where the tug was renamed as the Penn No. 4.
She is a twin screw tug rated at 4,300 horsepower.
In 2012, Penn Maritime was acquired by the Kirby Corporation of Channelview, Texas. Where she retained her name.
In 2013, the tug was outfitted with a Jak coupler system at Feeney's Enterprises in Kingston, New York.