How many tugs assist pilotage?

几艘拖船协助引航？

Pilotage is not compulsory.

引航是非强制的。

Pilotage at Qingdao Pilot Station resumed.

青岛引航站的引航业务恢复。

Pilotage advance of The Times, advanced and excellent culture.

领航时代前进的、先进的、优秀文化。

No, I do not require pilot-i am the holder of Pilotage Exemption Certificate.

不，我船不要引航员，我持有引航豁免证书。