ABSTRACT
Deck officers simplify the problem of ship berthing, whether made on her own or with tugs assistance, to maintain proper local lateral velocities fore (at the bow) and aft (at the stern). Both movements are able to be measured by an onboard doppler log (with sensors in the mentioned locations), an onboard docking system (as the satellite-based one with two antennas, or where the linear velocity vector, e.g. from a satellite system, is integrated with the rate of turn from a gyroscopic sensor, or in which inertial sensors are finally applied), or a docking system ashore, if applicable. Some terminals report a maximum allowable lateral approach speed for various weather conditions and ship sizes. By default, the essentially parallel approach is therein assumed.
