Built in 2012, by Bollinger Shipyards Incorporated of Lockport, Louisiana (hull #582) as the Ocean Sky for Crowley Marine Services Incorporated of San Francisco, California.
She was the fourth Ocean class tug constructed for Crowley Marine Services Incorporated by Bollinger Shipyards Incorporated.
Powered by two, Tier II compliant Caterpillar C-280-12 diesel engines. With Reintjes LAF 5666 reduction gears, at a ratio of 6.857. Turning two, four bladed, 153.5(in)(3.9m) diameter, Cu-Ni-Al, controllable pitch propellers. The tug's engines are capable of being upgraded to Tier III, or IV compliance when, and if necessary. She is a twin screw tug, rated 10,880 horsepower. With one, Berg (Electric) VFD 850 horsepower (634kW) bow thruster.
Her electrical service is provided by one, Tier II compliant, 340 kW Caterpillar C-18 auxiliary generator. With two 1475 KVA shaft generators, and one, Tier II compliant, 125 kW, Caterpillar C-6.6 generator set. The generators are all capable of being upgraded to Tier III or IV compliance, if necessary.
The tug's capacities are 251,346 gallons of fuel oil, with the ability to handle 2,118 gallons of fuel oil overflow, 1,037 gallons of dirty oil, 1,225 gallons of oily water, 1,225 gallons of hydraulic oil, 16,868 gallons of fresh water, 6,474 gallons of oily water, 4,880 gallons of sewage, 2,900 gallons of lube oil, and 1,436 gallons of foam. The tug is double hulled, and designed to prevent any overboard discharges of fuel or any fluids.
She is rated "DP 2" (Dynamic Positioning) which, is a computer-controlled system that automatically maintains a vessel's position, and heading by using its own propellers and thrusters. Position reference sensors, combined with wind sensors, motion sensors and gyro compasses, provide information to the computer pertaining to the vessel's position. And the magnitude and direction of environmental forces affecting its position. The Ocean Sun and Ocean Sky are 10(ft) longer than their predecessors to accommodate the space requirements for the "DP 2" machinery.
The towing gear consists of a INTERcon DW275, hydraulic, "waterfall" style towing winch. Outfitted with 3,000(ft) of 2.5(in) wire on the upper drum. And, 4,200(ft) of 2.75(in) on the lower drum. She is also fitted with an auxiliary towing winch, outfitted with 300(ft) of 1(in) wire.
She is fitted with deck cranes, one mounted on the aft deck with a 25 ton capacity. And, one mounted on the bow with a 5 ton capacity. With 200 MT Triplex wire guide pins. As well as, 350 MT Triplex "shark jaws." And, a 6(ft)(1.83m) diameter full transom stern roller.