A tanker intended to carry oil from shelf fi elds not accessible to pipeline systems. This tanker type is designed to operate in conjunction with off shore loading installations such as submerged turret loading (STL) system, a subsurface loading station (UKOLS), floating storage and offloading unit (FSO), floating production, storage and offloading units (fpsos), or articulated loading platforms (ALP/SPM). The shuttle tanker is in light condition prior to docking with a loading buoy making conventional thrusters non effective in bad weather and heavy seas. As a result, the vessel might have to wait for several days before it could start loading, which costs time and money. To avoid such operational problems, the shuttle tanker should have good dynamic positioning capabilities: the ability to position itself while docking at a loading buoy, and its ability to maintain that position while loading
