Built in 1976, Scheepswerf Jonker and Stans-Hendrik Ido Ambacht of the Netherlands (hull #338) as the Union Four for Union de Remorquage and De Sauvetage of Antwerp, Belgium.

In 1990, the tug was sold and renamed as the Canadian Express.

In 1990, she was sold and renamed as the Traders Express.

In 1990, the tug was acquired by McAllister Towing Limited Montreal. A subsidiary of the McAllister Brothers Towing Company of New York, New York. Where she was renamed as the Offshore Monarch.

In 1998, the tug was acquired by the Offshore Express Company of Houma, Louisiana. Where the tug retained her name. However, she was operated under a Peruvian flag.

In 2015, she was scrapped.

Powered by two, EMD 16-645E5 diesel engines, with Reintjes reduction gears. Turning two, fixed pitch, propellers, mounted in kort nozzles. She was a twin screw tug, rated at 5,750 horsepower.

The tug's electrical service was provided by two, 125kW generator sets. Her capacities are 122,576 gallons of fuel, 5,679 gallons of lube oil, 528 gallons of hydraulic oil, and 7,925 gallons of potable water.

Her towing gear consisted of a hydraulic, double drum, Brusselle anchor handling winch. Outfitted with 2,952(ft) of 2(in) diameter towing wire on each drum.

(Mac Mackay, Bob Beegle)