Built in 1965, by the Diesel Shipbuilding Company of Jacksonville, Florida (hull #123) as the Mako for Parallel Marine Incorporated of Weston, Florida.
In 2005, the tug was acquired by the P and L Towing Company of Miami, Florida. Where the tug was renamed as the Heidi.
Powered by two, Detroit Diesel 16V92 diesel engines. With Twin Disc MG-527 reduction gears, at a ratio of 5.17:1. Turning two, 64(in) by 44(in), four bladed, stainless steel, fixed pitch propellers. She is a twin screw tug, rated at 1,800 horsepower.
Her electrical service is provided by two, 60kW, Perkins MP-60 generator sets. The tug's capacities are 9,500 gallons of fuel, 35 gallons of lube oil, and 2,000 gallons of water.