Predicting drift characteristics of persons-in-the-water in the South China Sea

Abstract

Maritime accidents occur with alarming frequency. Finding wrecked objects accurately and efficiently is the primary goal of search and rescue (SAR) operations at sea. The objective of this study is to determine the drift characteristics of persons-in-the-water (PIWs) in the South China Sea via field experiments in conjunction with Monte Carlo simulations. A series of maritime drift experiments were carried out in the South China Sea using dummy buoys in vertical and horizontal positions to obtain 589 valid samples. This data was used to establish drift models of the dummies in two positions: the AP98 leeway drift model and the dynamics drift model. Finally, Monte Carlo simulations were used to compare the vertical PIW and horizontal PIW drift models. Results indicate that the drift trajectory of the vertical PIW is to the right of the horizontal PIW; the drift distance of the vertical PIW is smaller than that of the horizontal PIW. Their jibing frequencies are 5.3% per hour (horizontal PIW) and 7.1% per hour (vertical PIW). The dynamic drift model is more accurate than the AP98 leeway drift model for predicting vertical PIW drift trajectory. The two drift models can be used in combination, however, for the horizontal PIW. The results of this work may provide theoretical support for drift prediction of PIWs at sea, which is of great significance for maritime SAR operations in the South China Sea.