Ships have proven to be effective mode for 80% of global commodity trade transported by sea. Working at ships poses a high risk. According to Heinrich, 88% of accidents at work can be prevented. It means that improving behaviors of the sailors can prevent the accidents up to 88%. This research was done on the sailors to find out their behaviors in applying the self-protecting equipment (APD) to prevent the accidents. The research population consisted of 150 1st to 4th grade student-officers attending nautical and engineering departments. The research used is a quantitative methodology with questioner dissemination. The result shows that knowledge and understanding about APD and the risk of not using the APD were high. However, the percentage of the APD application and maintenance were still low. Therefore, the effectiveness of its use was not optimal. The research recommended a good APD maintenance by the ship management on a regular basis and scrutiny towards the APD availability on the ship.