Built in 1999, by Dakota Creek Industries of Anacortes, Washington (hull #34) as the Tan'erliq for Crowley Marine Services.
She was the first of two 153(ft), 10,192 horsepower enhanced tractor tugs specially designed and developed for Crowley for service under a contract with Alyeska Pipeline Service Company for tanker escort operations in Valdez Harbor and Prince William Sound, Alaska.
Due to the conditions of the tug's intended service environment, she was designed to demanding specifications as the most powerful cycloidal propulsion tugs ever built, capable of a bollard pull of 208,000 pounds and a vessel speed of 14.5 knots. In sea trials, the vessel was found to deliver in excess of 210,000 pounds of bollard pull and a top vessel speed of just under 16 knots.
Powered by two Caterpillar 3612 engines driving twin Voith Schneider cycloidal propulsion units for a rated 10,192 horsepower.
She is outfitted for tanker escort services, ship handling, firefighting, and emergency and spill response in Alaskan waters. Design features include a hydrofoil-shaped skeg, welded steel construction, transverse framing, wing tanks, and ice belting