A pilot vessel on pilotage duty at night will show sidelights and a sternlight （）.

Due to lapse of time the risk in these areas to surface navigation is now considered （）than the ordinary risks of navigation，but a very real risk still exists with regard to anchoring，fishing or any form of submarine or seabed activity.

As these features are not all charted，special caution should be exercised （） vessels navigating in the vicinity.

The distance between the surface of the water and the tidal datum is the （）.

The distance between any two meridians measured along a parallel of latitude and expressed in miles is the （）.

The period at high or low tide during which there is no change in the height of the water is called the （）.

A vessel is entering port A for the first time and has a Pilot conning the vessel. The Master is unsure that the Pilot is taking sufficient action to prevent a collision. What should the Master do（）.

The Earth has the shape of a(n) （）.

On a voyage from Capetown to London，the favorable ocean current off the coast of Africa is the （）.

Lateral movement of the vessel to leeward of its course defines （）.