Your vessel is anchored in an open roadstead with three shots of chain out on the port anchor.The wind freshens considerably and the anchor begins to drag.Which action should you take FIRST（）.

Mariners should ensure correct（）of aids to navigation during twilight periods when some lighted aids to navigation are lit while others are not.

That（）is not caused by shallow water.

A（）is the intersection of the surface of a sphere and a plane passing through the center of the sphere.

Sometimes lights are（）by fog，haze，dust，smoke，or precipitation which may be present at the light，or between the light and the observer，and which is possibly unknown by the observer.

Conventional anchors are least likely to hold in a bottom consisting of（）.

Pilotage in this country is（）.

When turning a ship in restricted space with a strong wind，it is normally best to（）.

You are docking a vessel in a slip which has its entrance athwart the tide.You land the ship across the end of the pier，stemming the tide，preparatory to breaking the ship around the corner.You have one tug to assist．Where would you generally tie up the tug（）.

If a ship has sternway，with accommodation block aft，she may settle with the wind（）.