Built in 1967, by Marinette Marine of Sturgeon Bay, Wisconsin as the YTB 793 (Piqua) for the United States Navy.
Her Keel was laid down on the 29th of September 1966, she was launched on April 25, 1967 and delivered to the Navy on the 10th of July 1967. The tug placed in service at the 1st Naval District at Boston, Massachusetts. She was later reassigned to Holy Loch, Scotland in 1964 to 1970.
She was placed out of service and struck from the Naval Register on March 13, 2001.
The tug was sold by the Defense Reutilization and Marketing Service (DRMS) to McAllister Towing and Transportation of New York, New York where she was renamed as the Ellen McAllister on November 20th, 2001.
In 2007, she was rebuilt and reconfigured. Her single Fairbanks Morse main engine was removed and replaced with two Caterpillar 3516B diesel engines driving two Schottel SRP 1012 "z-drives" for a rated 4,000 horsepower. Her original underwater submarine fendering was kept but refurbished.
The tug's capacities are 20,000 gallons of fuel oil, 710 gallons of lube oil, and 1,290 gallons of potable water.
Her fire fighting equipment is driven by a 6-71 engine with a Goulds fire pump rated for 2,000 Gallons Per Minute. The pump is tied into two monitors rated for a 1,500 gallon foam capacity.
The towing gear includes a JonRie InterTech Series 200 bow winch fitted with 450(ft) of 7(in) Neutron rope.