How to anchor your boat

Taking anchor in a beautiful bay for a spot of lunch, or perhaps a swim, is one of the many joys of boating. But for many skippers and crews, the process can feel daunting.

To help make anchoring safer and less stressful, experienced Motor Boat Skipper Karl Fisher shares his top advice with us.

Prepare the Ground Tackle

The first thing to do is have a look at your ground tackle and make sure you have the most suitable kit for the type of anchoring you will be doing. There are several different types of anchor; all have their own characteristics, and each vessel will have limitations around safe and effective stowage and deployment.

Anchor types

Traditional designs include Delta, CQR/Plough, Bruce, Fisherman’s, Danforth, and Grapnel. Modern designs like the Spade, Manson Supreme, Manson Boss, Rocna Original, and Rocna Vulcan offer excellent holding power across seabed types.

Anchor cable

Decide if you’re using all-chain or a chain/warp (rope) combination. In a combination, we always have 10m of chain between the anchor and the warp.

Sizing

The diameter of your chain and warp should be determined by the size, weight and design of your boat; as recommended by the manufacturer. The chain should be galvanised or stainless steel and the warp stretchy. Any connecting shackles or swivels should be seized with Monel wire.

Fittings

Also, is the bitter end lashed to the boat? Never attach it with a shackle. Instead, use a lashing or thin rope that you can cut quickly with a knife if you need to lose the anchor and cable in a hurry. The anchor itself should be quickly deployable, attached to the boat by a lashing or a split pin.

Length

The length of your anchor cable will depend on the depth of water you plan to anchor in, the amount of appropriate stowage space you have, and the type of anchoring you do (brief lunch stops or overnight cruising, sheltered bays or moderately tidal rivers, etc.)

The amount of chain and warp used must be far more than the depth of water to allow a good length to lie on the seabed. This provides the horizontal pull on the anchor that makes it dig in. Some people lower a weight (called an anchor chum or angel) down the anchor cable to give the anchor a better bite onto the seabed, giving a greater catenary to the line and reducing the swinging circle of the boat. If too little chain and rope is used, the boat may drag at high water. Marking the chain and rope in some way can also make it easier to prepare the correct amount (some people use cable ties, some use silk ties, others use patented plastic chain markers).

With chain, use four times the maximum depth, and with a combination of chain and warp use six times. This means that it is important to allow plenty of room behind the boat when anchoring and for the swing, remembering that not all boats will turn at the same time. Yachts tend to lie with the tidal stream and motor boats more often into the wind.

Choosing an Anchorage

Top tip: Look for a spot that’s sheltered, flat, and with good holding ground.

There are many recommended small craft anchorages marked on nautical charts with details listed in local almanacs and pilot books. You want to find somewhere that is sheltered from the wind, stream and swell, somewhere with a reasonably flat seabed, and with good holding for the anchor.

What to Avoid

Prohibited areas, fairways, channels, wrecks, underwater cables, oyster/mussel beds, or marine conservation zones.
Seabeds of rock, gravel, weed, or kelp (poor holding).

Check the chart and almanac and know how to interpret the symbols. The ones to watch out for include anchoring prohibited, foul ground, wrecks, underwater cables, underwater obstructions, tidal races, seabeds where there are lots of rocks, weed or kelp, and deeply shelving bottoms and ledges.

It is also important to keep clear of marked channels, fairways, prohibited and restricted areas, oyster and mussel beds or marine conservation zones, where you may obstruct other vessels or break the local bylaws.

Seabed Types

Mud: Good holding for most anchors.
Silt: Generally good.
Clay: Strong once set; sharp anchors set best.
Sand: Variable; large-surface anchors hold better.

See what the chart says about the nature of the sea bed and think about how your anchor will hold. Mud is good for most anchor types, but those with a large surface area will be more reliable. Silt is good for most anchor types. Clay, once set, is a good holding for most anchors, but a sharp tip will set more readily. Sand is variable; depending on the hardness of the sand, an anchor with a large surface area is preferable. Gravel, rock, weed and kelp are generally not very suitable for effective anchoring.

Check the weather forecast

Stay clear of a lee shore (wind blowing onto land). Aim for a weather shore instead.
Check the forecast for wind shifts that may change conditions.
Confirm tidal depths so you remain afloat at low water and anchored securely at high water.
Cross-check electronic data with charts, almanacs, and tidal curves.

Make sure that you are not about to anchor on what is, or may become, a lee shore, with the wind blowing onto the land. Always try to anchor on a weather shore, where the wind is coming off the land. Check the forecast to make sure that any wind shift during your stay will not put you on a lee shore and always have an escape route, day and night.

Check the depth and tide information. Will you still be afloat at low water, with a safe under water clearance beneath your keel? Have you let out enough cable to remain anchored at high water? Even if you can get tidal information from your electronic devices, it is best to check it against the almanac and the relevant tidal curve.

Coming to Anchor

Approach carefully: Leave space from other boats and hazards, aligning with how others are lying.
Prepare the windlass: Ensure it’s powered on, secure, and the crew knows safe handling procedures. Keep hands and feet clear of moving parts.
Lower the anchor: Stop the boat, lower until it touches bottom, then pay out cable as the boat drifts or gently reverse.
Set the anchor: Once the cable is secure, go astern to tighten and check holding.

After you have chosen your anchorage and selected a nice gap between the other boats that is free of hazards and danger, and where you are unlikely to drop your anchor over somebody else’s cable, have a look at how other boats are lying and approach your spot from a similar angle.

If you are using a windlass, make sure it is turned on and set up ready to use. Make sure the crew are briefed on the safe use of the windlass and associated equipment. Keeping limbs away from moving parts is essential and make sure the anchor locker lid is secured so that it doesn’t come crashing down on fingers and toes. When there is power supply to the windlass, do not get any limbs, fingers or toes anywhere near the moving parts of the windlass.

Stop the boat over your chosen position and keep the boat stationary as you lower the anchor safely, but smartly, until the crew feel it drop onto the seabed. Continue to lower the anchor cable as the boat drifts back with the stream/wind, and bear in mind that in light conditions you may need to reverse slowly while the crew pay out the anchor cable to the required length. Once the correct amount of cable is lowered, and the cable has been secured to the boat properly (by means of a chain lock on a windlass or by means of securing the cable to the boat’s cleat), engage astern to pull the cable taut and check holding.

Monitor for Dragging

Watch a shore transit to confirm you’re not moving.
Use an anchor alarm on your navigation system or smartphone.
Check with a depth sounder for changes.
Feel for unusual vibrations in the cable.

You will also need to guard against dragging. For example, find and observe a transit off the beam of the boat to monitor your position and see if you are dragging. You could use an anchor alarm on your electronic navigation system or smartphone application that will sound if it detects your anchor is dragging. You can also use the depth sounder as a means to monitor if you are dragging into shallower or deeper water. In addition, if you are dragging, you can often feel and/or hear a vibration or excess movement in the anchor cable.

Anchor Watch

Display an anchor ball by day and an all-round white light by night.
Record position, depth, and time in your logbook.
Set up an anchor snubber to protect your windlass.
Add a split pin or lashing across the bow roller to prevent cable jump-out.

Make sure that you monitor the situation when the boats in the anchorage start to swing, around the time when the tide turns or perhaps a wind shift. If you are in an area you do not know, consider using a tripping line on your anchor, so that you can indicate to other boats where your anchor is. The tripping line can also assist you in recovering your anchor when leaving the anchorage.

Once anchored, you will need to display an anchor ball by day and an all-round white light by night. Also make a record in the boat’s log book, recording the fact you are anchored, including the depth and position etc.

If using chain, attach a length of line, preferably stretchy nylon, to the chain using a rolling hitch, then make the line fast to a cleat and run the chain out until it goes slack and the tension is taken on the line. Apart from taking the pressure off your expensive windlass, this also acts as a snubber, and is excellent practice. If there is any swell, put a split pin between the bow roller cheeks or tie a lashing across to stop the cable from jumping out.

Plan Ahead and Stay Calm

Overall, although anchoring can seem daunting, it needn’t be a stressful process. With a bit of forward planning and a calm approach, anchoring can be safe and hassle free. Make sure you have the correct tackle and anchor line, find a spot with a suitable seabed and minimal hazards, plan your approach, take your time to lay anchor in a controlled manner and ensure you have a good hold, then you’ll be able to sit back, relax and make the most of some magnificent anchorages, wherever your cruising adventures may take you.

Order Anchor Lines from Advanced Rigging

If you are unsure of whether you have a suitable anchor line or are in need of a replacement, Advanced Rigging and Hydraulics offers a variety of high quality mooring and anchor lines to suit every size of boat. Whether you need a heavy duty line for your large motorboat or a robust light-weight line for your performance race yacht, Advanced Rigging can find the right product to suit your requirements.

Call +44 02380 454 280 or email [email protected]

How To Anchor Your Yacht