Built in 1977, by Modern Marine Power Incorporated of Houma, Louisiana (hull #20) as the Petrel for the Allied Transportation Company of Norfolk, Virginia.
In 2012, the Allied Transportation Company was acquired by the Kirby Corporation of Channelview, Texas. Where the tug retained her name.
In 2017, she was removed from active service. And was "laid up" at the Kirby Corporation's yard at Mariner's Harbor in Staten Island, New York.
In 2017, the tug was acquired by Northstar Marine Incorporated of Clermont, New Jersey. Where she was renamed Northstar Integrity.
With Twin Disc 530 reduction gears, at a ratio of 7.27:1. She is a twin screw tug, rated at 1,800 horsepower.
Her electrical service is provided by two, 40W generators, driven by two Detroit Diesel 4-71 diesel engines.