Exploration of the Drift Motion Characteristics of Typical Chinese Offshore Fishing Vessels

The drift motion of a maritime distress target is the collective result of the balance of forces that comes from wind, currents and waves. The drift properties vary from one type of object to another. The objective of this paper is to explore the drift motion characteristics of typical Chinese offshore fishing vessels. First, the forces on the unpowered fishing vessel were analyzed, and the calculation methods of various external forces were determined. The dynamic model of the unpowered fishing vessel was established by considering the appearance and floating state of vessel. Furthermore, the motion quadrants of different wind and current angles were established to explore the downwind deviation characteristics of the unpowered fishing vessel. Therefore, the drift motion model of the unpowered fishing vessel was established. Finally, a series of field experiments were conducted in South China Sea to provide data source. The reliability of the drift motion mathematical model is analyzed by comparing the calculated results with the test results. Considering the large number of the typical offshore fishing vessels in South China Sea, and their high accident rate, the drift motion model for this type of vessels are expected to be implemented into more search and rescue (SAR) models by SAR organizations.