Anchoring for Smarties

by Cruising Editor on 6 Nov 2006 You may have anchored a thousand times – but are you doing it as safely as you could? Do you sleep at anchor secure in the knowledge that the boat can cope with almost any eventuality? Here’s a step-by-step guide for dummies to the process of anchoring safely. Check it out against YOUR method…

On arrival in an anchorage, first consider how the boats there are anchored. Most will be swinging on a single anchor warp. But in heavy weather, some may be using an anchor weight; some may have two anchors set off the bow, or one off the bow and one set astern. Some may be on permanent moorings. When the wind or current shifts, the vessel with an anchor weight or two bow anchors set, will swing in a shorter radius than boats on a single anchor. Vessels anchored for and aft won’t swing at all. Those on permanent moorings will pivot around their bows, but move very little. In very light air, boats with all chain anchoring systems may not swing as far or as quickly as those riding a mostly nylon warp.

As the newest arrival, you must anchor to keep clear of boats already at anchor. Make sure you allow for any change in wind direction and strength. It is always safer to leave extra space around your boat

Position your boat with the bow to the wind (or the current, if that is stronger), roughly equidistant from your nearest neighbours in the approximate location you wish to be in when anchored. Make sure you will have ample water beneath you at dead low tide.

IN NORMAL CONDITIONS, A SAFE MINIMUM ANCHOR SCOPE RATIO IT 5 TO 1 (warp or chain length to depth). In heavy weather, 7 to 1 or more. Depth is the depth of water at high tide, plus the height from water line to the bow roller. Scope is the actual amount of anchor line paid out when the boat is safely anchored. For example, if high water is 20ft deep and your bow roller is 5 ft above the water, you need 125 ft (ie. 5 times 20 plus 5 ft) of scope to anchor. REMEMBER, PUTTING OUT TOO LITTLE SCOPE IS ONE OF THE MOST COMMON MISTAKES A SKIPPER MAKES WHEN ANCHORING.

While still hovering above the spot where you intend to lower your anchor, take another look around your boat. Don’t set your anchor close alongside or close off the bows of other vessels. If you do, you may well swing into them if there is a wind shift. It is usually safe to set an anchor close astern or off the quarter of another boat. Look also at the direction in which the warps and chains of nearby boats are pointing. A boat may have a second anchor set off in your direction, which you may foul if your anchor drops on top.

If winds are very light, don’t assume that everyone’s anchor is positioned straight out before the bow. In calm conditions, anchor warps, especially chains, may be stretched out in the direction the last real breeze blew from. You can always ask the skipper of a nearby boat where his anchor lies.

If all is well, circle back around to your intended final resting spot and then slowly coast forward the approximate distance of your planned scope.

Stop the vessel completely with a short burst of reverse power. WHEN YOUR VESSEL HAS LOST ALL WAY AND IS AT A COMPLETE HALT, LOWER THE ANCHOR. If you have any way on at all, your anchor chain will drag over the anchor once the boat drops back and may foul the anchor.

When you let go the anchor, don’t let the chain and warp go screaming out to pile on itself. In stead, lower the anchor quickly, paying out the warp or chain (hand over hand or with the windlass) until you feel the anchor rest on the seabed. Signal to the helmsperson to put the engine in very slow reverse, so the vessel just begins to make slight sternway about the time the anchor touches the bottom. If it is windy, leave the engine in neutral and let the boat’s windage and motion provide the backing propulsion. As the boat continues to back slowly, also fee out the anchor line slowly, maintaining a slight tension on it, so that it is laying our straight on the seabed, instead of in a pile.

With the boat still backing slowly and with about half of the scope out, hold the anchor line firmly until you feel the slack is taken up and the anchor is tugging. Feed more anchor line out, but keep tension on so the anchor is being set straight.

Pass the anchor line around the bollard to make it easier to hold. Snub up firmly, just long enough to feel it tugging for a second, then ease off. Repeat this snub and feed pattern several times. On a larger vessel, with an all chain anchor line and heavy ground tackle, you would be using the windlass gypsy for this task, alternatively braking and releasing the drum.

This gentle snubbing/feeding action while backing down the boat is the surest way to make an anchor set. Yet it is a technique very few skippers seem to employ. It gives the anchor an opportunity to right itself, penetrate the bottom surface and gradually dig in.

If the anchor has taken hold, the boat will come to an abrupt halt, firmly setting the anchor.

Once the anchor is set to your satisfaction, there are two more securing devices that can be used to good effect:

THE SNUBBER: This handy procedure takes the strain off the windlass, and allows for stretch in the anchor chain system.

THE ANCHOR WEIGHT, which reduces both yawing (which in turn reduces drag on the anchor) and your swinging circle (handy in a crowded anchorage) – the commercial versions of this excellent anchoring tool go by the brand names of ‘Anchor Buddy’, ‘Sentinel’, ‘Angel’ and ‘Kellet’.

Sail-World Cruising would like to thank Anchor Buddy for the information used in this article