Abstract
The increase tendency to the ship's collision related to the visual perception of a stern light in recent years is remarkable, and the investigation of the cause should be carried out. Judgment reports by the Japanese Marine Accident Inquiry Agency of 30 years from 1970 through 2000 has been investigated about human errors related to the visual perception of a stern light. 98 cases of the ship's collision are picked out, and the main results of this study are shown as follows ; (1) In the distance between two ships when a stern light is checked visually for the first time, about 90 percent of the cases are below the distance regulated by COLREG. The mean value of the distance between two ships is 1nm (nautical mile) , and standard deviation is 0.7nm. (2) The field factor at sea is 2〜3 at night. (3) About 3/4 of the cases are pointed out the time period within 20 minutes after checking the target visually. (4) The calm weather condition becomes a factor to cause the human errors at sea. (5) There are three factors of human errors related to the visual perception of a stern light : 1. Psychological factors, 2. Psycho-social factors, and 3. Physiological factors. (6) In the case of ship's collision related to the visual perception of a stern light, by classifying based on the GEMS dynamic model, the error (Mistake) is more than the error (Ship).
