Anchoring safely

Resting at anchor on your boat should be a pleasant and relaxing experience, either sipping a sun-downer on board or ashore, or sleeping soundly to the gentle sound of lapping waves against the hull.

Actually, anchoring can be quite a stressful experience for a lot of boat owners, and a cause of numerous insurance claims. But with a little advice and reasonable planning, apprehension can be overcome.

First things first

• Check that your anchor size/weight is appropriate. Check the length, weight and condition of your chain or warp, and shackles. The length of line you carry will depend on the size of your boat, and what depth of water you are likely to be anchoring in.

• Chain holds better than line because anchors need horizontal pull to work. But weight, cost and lack of stretch are considerations. Some people go for a combination, with chain lying on the bottom. The bitter end of the chain needs to be securely attached.
  Some owners prefer rope or webbing that can be quickly cut in an emergency.
  

How much line do I need?

• The generally accepted stance on how much line to deploy is 3-4 times the depth of water you are in for chain, and 6-8 times depth for warp.

• Remember though to check the tidal range where you are and allow for the maximum possible depth. In rough weather line out use up to 10 times the maximum depth of water. Remember ‘if in doubt let it out’; your line or chain will do more good on the seabed than in your locker.

• Measuring the amount of line you are letting out can be done by marking it with paint or tags, or laying out multiple lines (flaking) to a known length on your boat. To avoid the risk of injury consider a rope stopper secured to a forward cleat and wrapped around the chain 3-4 times to control the drop.

How can I stop the anchor from breaking free?

• A soft ‘snubbing’ line, taking the load off the chain at the top, can act as a damper. Or lowering a weight ‘chum’ down the chain on a separate line will help dampen snatching. Also consider setting a small sail aft to preventing excessive swinging and minimise windage.

Where should I anchor?

• Charts and almanacs show recommended locations. Pick one that ensures you are being blown offshore in the likely wind direction for the duration of your stay, then take note of the sea bed type and location of any obstructions or underwater cables.

• Allowing for a full 360 degree swing, and avoid anchoring over other boat’s lines. If you snag another anchor, try to raise gently and use a boat hook to clear the chain as close to the bottom as possible.

• Take time to find your preferred spot to drop anchor and fall back on an anchorage, check wind and tidal drift, and even do a practice dropping run. Check and check again. For the actual drop, ensure you’re moving slowly astern and that the anchor is pulled out at a steady rate.

Anchoring safely

• Drop the anchor until it is on the sea bed and then motor slowly astern, paying out the correct length of line at the speed you are moving, your bow should dip when it has ‘dug in’. Allow the boat to settle and then check by gently increasing the motor load in astern up to ¾ revs. Further checks through taking transits ashore, setting depth or GPS anchor alarms can also be used.

What type of anchor is best?

• There are many types, all of which have pros and cons. Generally, a Bruce or GQR will perform best in sand or mud, and a Fisherman or Danforth is good with rock or weed.  If the anchor fouls you can try pulling at it from different angles or dropping a weighted loop of line down the chain to pull off the anchor directly. A driver may be the only option, but if you are putting boat and crew in danger by being snagged by an anchor it may be advisable to tie a couple of fenders to the chain and get yourself free.

Whilst the information is believed to be correct, Navigators & General takes no responsibility for any loss or damage however caused.