Near-miss density map for safe navigation of ships

The purpose of the present study was to identify ship near-miss areas and determine the relative densities of the areas. The findings were used to develop a near-miss density map for safe ship navigation and the prevention of collision between passing ships. This study used big data of merchant vessel and fishing boat location for 1 year in 2014. The databases were interpolated using a time unit of seconds to extract near-misses between ships based on data for exactly the same time. Furthermore, to determine near-misses, the distance and time to closest point of approach were calculated for different pairs of approaching ships. The near-miss density of each grid of the map was depicted by means of the RGB color code. The concept was validated by using it to depict the distributions of actual collision accident locations that occurred in the southern coastal sea of Korea between 1997 and 2016. The highest near-miss area was found to be in the approach of Busan Port, where actual collision accidents also occurred most frequently. The results showed that 73.3% of the near-misses in the study area involved fishing boats. In addition, out of the 25 collisions that actually occurred in the study area in 2014, 19 (76.0%) were related to fishing boats, and this was reflected by the map developed in the present study. The findings of the study can be used to develop a special near-miss density nautical chart for use as a navigation safety material by deck officers. Such chart would facilitate the exercise of precaution in passing through dangerous areas.