Anchors
Anchors – who must carry one?
If you are operating in unprotected waters (outside the waters contained by any breakwater or in any lake, river or estuary other than the waters of Cambridge Gulf or Lake Argyle) you must carry an efficient anchor and line. The anchor must be of a type that will hold in all sea beds and with enough line to suit the depths in which you usually operate.
Choosing an anchor
Provided it is a type that will hold in all seabeds, the choice of anchor is up to you. Most people choose one of the following high holding power designs:
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Danforth |
This is the most common type for trailer boats that do not stow the anchor below a bowsprit. It has excellent holding power in most bottoms, especially sand and is modest in price. |
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Plough or Coral Quick Release (CQR) |
This is more expensive than the Danforth because of its more complex construction. Its holding power is similar, but it has a better reputation for holding in mud. Also, it is better suited for self-stowing under a bowsprit. |
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Bruce or spade |
This is the best of all for bowsprit stowage and is gaining in popularity. However for small boats, where the anchor is stowed within the vessel, it is very cumbersome. |
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Standard Stockless – Admiralty pattern |
The sailors’ cap badge anchor looks old fashioned, but it is the best at piercing weed beds and it also works well in mud. Weight for weight it is one of the best all round anchors, but it can be inconvenient to stow. |
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Reef or grapnel |
Effectively a bundle of mild steel rods bent to make a grapnel, the reef anchor is too specialised to be acceptable as a boat’s sole anchor. For anchoring on a rocky bottom, though, it is a useful extra. Unlike a normal anchor, which can be near impossible to retrieve from rock, this will straighten out under a heavy load and withdraw. |
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Sea anchor or drogue |
If you plan to go boating offshore, then a sea anchor can be a valuable piece of equipment. Sea anchors, when set, will slow your drift and keep the bow of your boat into the wind and waves. This provides comfortable conditions when drifting in choppy seas. |
Anchor cables
An anchor cable may be all chain, or rope with a piece of chain joining it to the anchor. The chain is necessary for its weight, it allows a more horizontal pull on the anchor and acts as a shock absorber. It also reduces chafe of the rope.
The best anchor rope is nylon because it has a lot of stretch and great strength; next best is polyethylene silver line. If the rope is nylon, you will need at least two metres of chain; other rope will need at least three metres.
Your anchor and cable should always be ready to run freely at a moment’s notice.
Weather
Check both the existing and forecast weather before anchoring. This could influence whether you will use more cable, or even decide to move elsewhere. Strengthening winds blowing on shore (technically giving you a lee shore) should especially influence your decisions.
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Selecting a site
- If you have a choice of bottom in which to anchor (in other words it is not an emergency), sand is ideal, firm mud next best. It is better not to anchor on a weed bed both for environmental reasons, and because most anchors find it difficult to grip.
- Check that when have let your cable out you will have enough room to swing to wind or tide without hitting the bottom or other vessels.
- If you are in a tidal area, ensure that you will have enough depth at low water.
Preparing to anchor
Having picked the spot to anchor and determined that you have enough cable, at low speed turn your boat to face the wind (on a low wind day face the current, if any). Put the motor in neutral, then in reverse for long enough to get the boat moving astern.
Lowering
Lower the anchor (do not throw it) to the bottom, and pay out cable as the boat moves astern with the wind.
Setting
When the full scope is out, secure the cable and give the engine a short burst in reverse to ensure that the anchor has bedded in.
The scope
The critical element of anchoring is to have enough cable out – enough scope is the jargon. The scope is the ratio of the length of cable used for the depth of water. The absolute minimum is three times the depth of water, and five or seven is better. Strong current or wind or a choppy sea put more load on the cable and make a bigger scope more desirable.
Recommended scope
| Condition |
Scope |
| Calm |
3:1 |
| Fair |
5:1 |
| Moderate |
7:1 |
Monitoring
Once the anchor has set and bedded in, you should take a few bearings or line up some objects (transits) to check that the anchor is not dragging. If you notice that you are drifting off the bearing and you suspect that the anchor is dragging, place your hand on the cable and feel for any signs of the anchor bouncing along the bottom. This should confirm or reject any suspicions you may have. If the anchor is dragging and you have enough room, try paying out more cable. In most cases by decreasing the angle between the anchor and the boat (ie, letting out more line) will be all that is required to get the anchor to bite.
Securing the anchor line
The very end of the anchor cable should be secured within the vessel to prevent loss of the anchor. If not using the whole cable, the chosen length should be secured to deck hardware.
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Retrieving the anchor
There is no need to over exert yourself by pulling the boat up to the anchor: let the motor do the job while you – or your winch – retrieve the cable. You may need to indicate to the driver which way to steer.
Snagged
When the cable is vertical, it may be necessary to take a turn of it around the bitts and let the engine power break the anchor out of the bottom. If the anchor will not break out, slacken the cable, back off, and approach the anchor from different directions.
Maintenance
Your anchor and its cable (rope and chain) are part of your safety gear and should be ready to run at any time. A common problem with free running is the way the rope is coiled. If you coil the rope on the deck or ground and then drop it into the cable well or box, you must make sure that when the anchor is dropped it will be taking rope from the top of the coil – this may require you to turn the coil over. Taking the rope from the bottom of the coil will cause kinks and tangles.
Keep chain / rope tidy
Coil the rope and chain clockwise (rope may develop kinks otherwise) into the cable well or the dedicated box – ready for instant use. It is best to secure the anchor away from the cable to prevent it passing through a loop and tangling.
Rules and regulations
Channels and leads
Anchoring is prohibited in any channel, fairway, passage or leading lines unless you are in distress or obtain the permission of the Department.
Submarine cables
Anchoring is prohibited in the vicinity of telephone, submarine and power cables laid on the seabed. These anchoring prohibited areas are marked on marine charts and must be complied with.
Mooring areas
Anchoring is not recommended in mooring areas. You could foul your anchor on the moorings and, because the spacing of moorings is usually only a little more than needed for the vessels on them to swing clear of each other, you would be likely to hit other boats.
Ports
Ports have individual rules for small craft using their waters. The overwhelming intent is to avoid any conflict with large commercial vessels, so ensure that you do not anchor anywhere near where these vessels pass.
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