In the strictest sense, a liftboat is a self-propelled crane barge that can elevate itself above the water line. It is the cranes that make a liftboat such a valuable tool for building and/or renovating offshore oil and gas structures. A recent example of the working ability of these liftboats is the L/B Myrtle, a 137.5-ft. by 92-ft. vessel with a trio of 245-ft. legs, enabling the vessel to work in water depths of 180 ft. with a 15-ft. air gap. The vessel was built by Bollinger Shipyards in their Lockport facility and sent to Bollinger's Amelia, La. shipyard for the outfitting of the three legs. Montco Offshore, Inc., Galliano, La., owns the vessel. Montco owns six liftboats capable of operating in water depths from 75 to 180 ft.