Day Skipper - Part 2 - Anchors

There are five main types of anchors (or derivatives) used in motor cruisers:

	1. The Fisherman's anchor This is probably the most traditional design. It is excellent on rock, and folds flat for stowage. However, it is easily snagged, has low holding power and is difficult to recover without damaging the hull. It's the only anchor that can cut through seaweed effectively.
	2. The CQR or plough anchor This is the most commonly used anchor, with high holding power for its weight. You need to be careful that you don't trap your fingers in the hinges.
	3. The Danforth This has a good holding/weight ratio and can be stowed flat. It can be difficult to remove from mud.
	4. The Bruce anchor One of the two most recent designs, it has excellent holding power. However, it is awkward to stow in lockers because it doesn't fold.
	5. The Delta The most recent design, it is similar to the CQR, but rigid. It has very high holding power/weight ratio and can be launched and recovered using a similar stemhead fitting to the Bruce.

Boat size Chain size Anchor size Delta anchor only

6m (20ft) 6mm 8kg (18lb) 4kg (9lb)

8m (26ft) 8mm 10kg (22lb) 6kg (14lb)

10m (33ft) 8mm 13kg (29lb) 10kg (22lb)

12m (39ft) 8mm 18kg (40lb) 16kg (35lb)

14m (46ft) 10mm 24kg (53lb) 16kg (35lb)

17m (56ft) 10mm 34kg (75lb) 25kg (55lb)

20m (65ft) 12mm 47kg (103lb) 40kg (88lb)

If a combination of chain and rope is used, a minimum of 5m of chain is required in small craft, increasing to at least 10m in larger craft.

1. Choose a depth where you have sufficient chain and rope to allow four times the depth at high water if using a chain only, and six times the depth if a combination of chain and rope is used. Always use the chain at the anchor end. It will help the anchor to 'dig in' and not drag. Remember to calculate the cable length required based on the depth at high water.

2. Choose an area with as little tidal stream as possible. The less tide, the less hard the anchor and cable will have to work to keep you in the same position.

3. Look for a sandy or muddy bottom. That will provide the best holding ground. Rocks, stones and shingle will not hold so well.

4. If anchoring among other vessels, estimate the size of your swinging circle and remember that different types of boats will swing to the tide at different times, depending on the tide and the direction and strength of the wind.

5. Once the anchor has reached the bottom, move slowly astern to stop the chain and/or rope forming a pile. For the best results, it is vital to lay out the cable along the bottom.

6. Try lining up shore features in a transit to check whether you may be dragging your anchor. (It is important to remember that they may alter considerably if the wind or tide change direction).

7. If you have a radar, use it to check ranges of the shore regularly. Modern radars are excellent for giving accurate ranges, but are more difficult for providing accurate bearings.

8. If there is any chance of snagging the anchor, rig a tripping line, but make sure the anchor buoy isn't too inviting for other craft to use as a mooring. A weight fitted on the tripping line 2-3m below the surface will keep any slackness in the line at low water, away from passing propellers.

9. If you suspect that you may be dragging the anchor, let out more cable or rope. If that doesn't solve the problem, recover the anchor and try somewhere else.

10. If you get snagged and cannot recover the anchor and cable, mark it with a large fender and go to find help. Don't discuss in public the exact position of where you lost it because it is quite likely that you may be overheard and the anchor and cable could quite simply disappear overnight.

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