engaged on pilotage duty从事船舶引航值班;从事引航责任;从事领港任务
On-Duty Apartment值班公寓
be on night duty值夜班;值夜
On-duty hour勤务时间
On-duty sign值班牌
person on special duty特勤
on active duty现役;正在履行的义务
on lookout duty观风
on garrison duty守备