STCW definitely order that the officer of watch onboard a ship of more than 500 ton must have the ability to use radar and ARPA to keep the voyage in safe stage.

• STCW公约明确要求500总吨或以上船舶，负责航行值班的高级船员能使用雷达和自动雷达标绘仪保持安全航行。