The proximity of pack ice may be indicated by（）.

If a tow sinks in shallow water，you should（）.

All persons or vessels within the lock area，including the lock approach channels，come under the authority of the（）.

In most cases，when a large merchant vessel enters shallow water at high speed the（）.

A towing vessel should be on the crest of a wave at the same time as its tow and in the trough at the same time. The term used to describe this is（）.

A vessel showing a rigid replica of the International Code flag A is engaged in（）.

A vessel reduces speed without backing. The rate that her speed through the water decreases depends primarily on the（）.

As the weather was worsening and wind force rising to 8，my vessel（）were yawing within forty degrees of the compass.

On a twin-screw，twin-rudder vessel，the most effective way to turn in your own water，with no way on，is to put（）.

Topside icing that blocks freeing ports and scuppers（）.