Watch out when at anchor 

Tips for anchoring safely.

An anchored vessel is not underway, but as soon as its anchor leaves the bottom or drags then it is. Therefore, you may need to set an anchor watch to establish if your anchor is dragging, to warn others of your presence, or to ensure that you do not drift into danger.

Obviously, the level of effort depends upon the location of the anchorage, depth of water, type of ground tackle, wind, currents, waves, other traffic and so forth but it’s worth giving these things some thought before turning in.

Lights, shapes and sounds

Anchored vessels are dealt with by Rule 30 of the Colregs. It’s essential that you exhibit the appropriate lights and shapes at anchor and that appropriate sound signals are made in restricted visibility.

By day an anchor ball must be displayed. By night, a vessel of less than 50m LOA must exhibit at least one all-round white light where it can best be seen.

Clearly the purpose of the anchor light is to enable you to be seen by others so that they can take appropriate action.

An all-round light at the top of the mast may conveniently double as a masthead (steaming) light and stern light on “power-driven” vessels of less than 12m in length. However, is the top of the mast the best place to put or install an anchor light when the small craft that is bearing down on you is looking horizontally ahead? 

Consider displaying it where others might be looking. This may not be far from head height if you are anchored near a harbour entrance that someone is trying to navigate into in the dark.

The visibility ranges of lights specified in the Colregs are minima not maxima; so make sure that it is bright enough to be seen. 

When at anchor you can also use additional lights to illuminate your deck, if you have a deck light think about switching it on. These days LED lights do not use much power and using additional lights all help to make you more visible. This may also assist an approaching vessel to determine how you are lying and in which direction your anchor warp or chain extends.

Choosing an anchorage

When choosing an anchorage and when at anchor, it is well worth thinking about:

• The nature, size and characteristics of the anchorage;
• The prevailing and expected weather, sea and current conditions;
• Traffic conditions and situations which might affect the safety of your boat;
• Communication requirements;
• Engine readiness.

This will enable you to decide how best to monitor your position and what sort of watch you need to maintain while at anchor.

Read more safety information.