Built in 1981, by Modern Marine Power, Incorporated of Houma, Louisiana (hull #38) as the Perseverance.
In 1983, she was sold and renamed as the Mr. Bill G. .
In 1990, she was acquired by Tidewater Marine, Subsidiary Twenty Grand Offshore where she was renamed as the El Rhino Grande.
The tug was later acquired by Dann Ocean Towing of Tampa, Florida where she was renamed the Stephen Dann.
She is a model bow, twin screw ABS Maltese Cross A-1 Towing Service, Maltese Cross AMS certified tug. She is powered by two Caterpillar 3512 TA diesel main engines with Reintjes WAV 1050 reduction gears at a ratio of 5.00 : 1.00 turning via 8(in) shafts two 86(in) diameter by 66(in) fixed pitch four bladed stainless steel propellers .
Her electrical service is provided by two 75 KW generators driven by two 6-71 Detroit Diesels. The tug's capacities are 50,000 gallons of Fuel Oil, 800 gallons of Hydraulic oil, 1,900 gallons of Lube Oil, 5,600 gallons of Wash Water and 8,000 gallons of Potable water.
The tug's towing gear consists of an INTERcon double drum DD-175 towing winch outfitted with 2,000(ft) of 1.75(in) primary wire and 2,000(ft) of 1.75(in) secondary wire.