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Anchors

We recommend that you carry an efficient anchor and line when operating a vessel.

The anchor must hold in all seabed conditions and have enough line to suit the depths you usually operate in.

Anchor types

Bruce or spade

Bruce or spade anchors feature a three-claw design, which resembles a grappling hook. The claw-like structure has sharp edges on the flukes to enhance its holding power.

Positives

  • Can be stowed under a bowsprit.

Danforth

The Danforth anchor has two large, flat, triangular flukes attached to a long shank. The flukes are hinged at the shank and are designed to dig into the seabed, allowing them to orient themselves towards the seabed at an optimal angle.

Positives

  • Not suitable to be stowed under a bowsprit.
  • Excellent holding power in most seabeds, especially sand.

Plough or Coastal Quick Release (CQR)

Plough or CQR anchors are designed to resemble a farm plough shape, allowing it to hold well in various seabed conditions.

Positives

  • Excellent holding power, especially in mud.
  • Suitable to be stowed under a bowsprit.

Reef or grapnel

Reef or grapnel anchors typically have 4 or 5 prongs designed for rocky conditions.

Positives

  • Useful second anchor for rocky conditions.
  • Will straighten out under a heavy load and withdraw.

Standard Stockless Admiralty pattern

A standard stockless anchor has two flukes that pivot on the same plane perpendicular to the shank.

Positives

  • Good for use in weed and mud.
  • Good all round anchor.

Sea anchor or drogue

A sea anchor or drogue is typically shaped like a parachute.

Positives

  • Ideal for offshore boating.
  • Slows drift and keeps bow of boat facing wind and waves.

Anchor cables

There are 2 types of anchor cables:

  • All chain
  • Rope with a piece of chain joining it to the anchor.

The chain is necessary because of its:

  • Weight
  • Horizontal pull
  • Shock absorbent ability
  • Ability to reduce rope chafing.

The best anchor ropes are:

  • Nylon is very strong with lots of stretch.
  • Polyethylene silver line.

If the rope is nylon, you will need at least 2 metres of chain; other rope will need at least 3 metres.

Your anchor and cable should always be ready to run freely.

How to anchor

Preparing to anchor

Always check the weather forecast and tides before anchoring. 

Changing weather, tides and strengthening winds may determine whether you will use more cable, or even decide to move elsewhere. 

If you can choose where to anchor, choose sand or firm mud. Avoid anchoring in weed as it is can be difficult to grip and cause environmental damage.

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 under your vessel when the tide is out.

Lowering the anchor

  1. Turn your boat into the wind.
  2. Put the motor in neutral, then in reverse for long enough to get the boat moving backwards.
  3. Lower the anchor (do not throw it) to the bottom and let out cable as the boat moves backwards with the wind.
  4. When the rope/cable is fully out, secure the cable and give the engine a short burst in reverse to ensure that the anchor has dug in.
  5. Once the anchor has set and dug in, you should take a few bearings or line up some objects to check that the anchor is not dragging.
  6. Secure the end of the anchor line to the vessel to prevent loss of the anchor if all the line is let out by accident.

Ensuring you have enough rope or cable

The critical element of anchoring is to have enough scope. The scope is the ratio of the length of cable used for the depth of water.

The minimum scope is 3 times the depth of water.

Strong current or wind or a choppy sea puts more load on the cable and required a bigger scope.

Recommended scope

Condition Scope

Calm

3:1

Fair

5:1

Moderate

7:1

Monitoring the anchor

If you notice that you are drifting off the bearing:

  • Place your hand on the cable and feel for any signs of the anchor bouncing along the bottom.
  • If the anchor is dragging and you have enough room, try letting out more cable. In most cases, letting out more line will help the anchor to dig in.

Retrieving the anchor

Don't 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. 

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 should be:

  • Ready to run at any time, make sure that when the anchor is dropped it will be taking rope from the top of the coil, avoiding kinks and tangles.
  • Coiled clockwise into the cable well or the dedicated box, ready for use.

Rules and regulations

It is prohibited to anchor in:

  • any channel, fairway, passage or leading lines unless you are in distress or obtain the permission from the Department of Transport.
  • the vicinity of telephone, submarine and power cables laid on the seabed.

These anchoring prohibited areas are marked on nautical charts.

Mooring areas

Anchoring is not recommended in mooring controlled areas.

These areas are designed to only provide enough space for the moored vessels to swing clear of each other, so you are likely to hit other boats when anchoring in these areas.

Ports

Ports have individual rules for small craft using their waters. In general, avoid anchoring near any large commercial vessels or where they pass.