How to anchor a boat: A guide for beginners

Jessica Watson
Posted November 3 2016

One of the most basic misconceptions about anchoring is that you don’t simply rely on the weight of the anchor to hold you in place. A great big dead weight is the theory behind moorings, but lugging around that sort of weight just isn’t feasible on your average boat. Instead, anchors are designed to dig into the seabed and work with a length of chain to hold a boat in place. Anchoring is a bit of an art but getting it right is well worth the effort, ensuring you’ll be able to relax and get a good night’s sleep.

Choosing equipment

There’s no one size fits all solution when it comes to anchoring equipment - or tackle as it’s known. Small boats will get away with a light anchor with a short length of chain attached to rope, but bigger boats will require bigger anchors and heavy chain that will need to be deployed with a winch, preferably an electric one.

Manufacturers will provide a guide as to the length and weight of boat that their anchor is suited for, but to give you a general idea an anchor of around 20kg is going to be appropriate for a 10m boat. There are a number of speciality anchors that should be used for different seabed types, but the most common designs are Plough (also known as CQR), Bruce or SARCA (Sand and Reef Combination Anchor). Head over to Deckee’s products page to see a few great anchor reviews. 

Setting anchor

Another anchoring misconception is that you can’t simply arrive, stop and dump your anchor and chain. For an anchor to hold effectively, you need to come to a stop, head to wind and then let the anchor and chain out in a controlled manner as you slowly drift or motor backwards, digging the anchor in and laying the chain in a nice line along the bottom. When you’ve done this, don’t rush off right away; find bearings on shore and watch to check that the anchor is holding.

The basic rule of thumb is that you want to achieve a scope or ratio of anchor chain 5 times the depth of the water. You might get away with a little less in perfect conditions, but when things are looking less than pleasant you’ll need to aim for a higher multiple. Remember to factor the tidal range into this calculation, and of course, so your boat doesn’t end up on the bottom.

The perfect anchorage

You don’t want to be anchoring in a protected seabed, so check your chart and any environmental zoning. To add insult to injury, an anchor dropped on coral is also likely to catch and become difficult to retrieve, causing further damage as you do so. Parks and Wildlife often provide moorings in areas of environmental sensitivity.

You’ll also need to check the forecast for changing weather conditions that might see your lovely protected anchorage become a surf break or just uncomfortable. Your ‘swing room’ (the arc you may drift on your chain) will also be affected by changing weather and current. At first, you might be sitting in a lovely roomy bit of water, but think about what’s going to happen when you pull back on your anchor chain in the other direction. Will you find yourself nudging up to a rock or neighbouring boat that might not appreciate your encroaching on their carefully planned swing room? 

Anchoring accessories

Once your anchor and chain is beautifully laid out, you might want to think about a snubber or bridle which will take the load off the anchor winch and may help the boat sit more comfortably at anchor. A bridle will be essential on multihulls which are prone to skidding around erratically at anchor.

In situations where you’re particularly worried about holding or have limited swing room, you could consider deploying a second anchor off the bow or stern. But I’d encourage you to really think through retrieval strategies and possible tangles before giving this a go.

There’s also plenty of technology on hand to make anchoring easier. If you have a chart plotter on board, there’s every chance it has an option to set an anchor alarm to warn you if your anchor is dragging. There’s also a variety of apps that will do the same thing. Keeping it simple: one of the best things you can do is to drop a waypoint right on top of your anchor or keep your chartplotter tracking on to monitor your swinging, giving you a nice visual of any drifting.

While this post is more likely to be useful to those starting out on the water than those who’ve spent years on it, I’d love to hear any tips and tricks from the anchoring experts out there. And why not share a review of your preferred anchor, or one that didn’t live up to expectations?

2 people found this helpful. Do you?Thank Jessica Watson


Write your reply...
Jack and Jude
Deckee Pro  Posted November 4 2016
Good advice Jess -

We'd just like to emphasis that anchoring in coral country requires chain. Even in what looks a sandy bottom can be coral rubble that'll chaff through rope in an eyeblink.

Since starting out in '74, Jack and Jude have put down a hook many thousands of times and here's our thoughts on the subject.

Be polite - do not anchor too close to other boats. If someone does this to us, we ask them to shift. If they're upwind and our raised arms don't have the desired result we shift. Obviously they are idiots. We've had far too many middle of night near misses from this type.

A good anchor and ground tackle is not only more safe, it lessens the hours of worry making the whole business of cruising more fun. So get the best.

Anchor types, the never ending saga: Danforths are light, good in sand/mud but will get destroyed if stuck in coral. Admirality are heavy, dangerous, liable to attack crew, and hard to stow, but penetrate ribbon grass and kelp. CQRs are lazy puppies that often look up at you lying on their side waiting to be tickled. They are robust, can be broken free if stuck in coral, but let go at the oddest times.

We have all of the above on Banyandah. Our 45 lbs CQR doing the bulk of the work in our cruising life, so we had more than a few sleepless nights.

Nowadays we use a 20 kg Manson BOSS, bites first time, every time except once when we had to have a second go. It's a bit of a brute on the rollers, but once down, worth every cent. Digs into thick ribbon grass and all types of kelp. Only hiccup, shallow sand over rock where nothing gets a grip. We've written up a review of the BOSS here on Deckee

When anchoring we make a WP as our hook goes down, to not only make a lasting record, but if it should blow, we know that if we are within .03 NM of that WP, we have not shifted. Saves a heap of worry.

A few last words. We're not keen on tandem anchoring. We've done it in the past but have had a big mess picking it up, and couldn't do it if we had to get out of there fast. Same with two anchors in a Vee. Even worse if the wind shifts and they wind around each other. Bow and stern is good for streams in tight spots. But side on to big winds means your're in trouble. Like Jess said, think about retrieval. Then add heaps of wind and being blown about. Instead, buy good gear, bigger than you think, splash out on a quality powered winch and then enjoy the blue world with a lot less worry.
6 people found this helpful. Do you?Thank Jack and Jude
Captain Crayfish
Posted November 3 2016
Hi Jess, Having spent time flailing around on the end of a secure anchor in heavy winds with a very unfriendly reef downwind I sought help and was advised that a small sea anchor or drogue off the bow roller (not the stern) would tame the cavorting. Also an anchor buddy simulates a longer chain and snubbing effect I'm told.

I have yet to test these but anyone with thoughts on them I'd love to hear your viewpoint. Thanks.
5 people found this helpful. Do you?Thank Captain Crayfish
Jessica Watson
Posted November 4 2016
Thanks for all the tips! Some invaluable ideas and suggestions from many collective years on the water! Setting a sea anchor or drogue while at anchor is a really interesting idea, I can imagine it would be helpful, but I'd also love to hear from someone who's tried...

Sounds like we've had similar experiences with tandem anchoring Jack and Jude!
4 people found this helpful. Do you?Thank Jessica Watson
Mark Watland
Posted November 4 2016
Thanks for writing about anchoring, Jess. I’m sure many of your readers have great advice that they’ve learned from their anchoring experiences. Many years ago I learned the hard way how important it is to inspect your ground tackle regularly. I once lost an anchor when the pin in the shackle that connects the anchor to the chain loosened and fell out while I was anchored. Since that pin can be a weak link, it’s a good idea to “mouse” the pin to the shackle. Wrapping stainless steel locking wire (seizing wire) through the eye in the pin and then around the body of the shackle is a common method although many people simply use a nylon cable tie which assures that they won’t stab their fingers with ends of locking wire when handling the anchor on deck. But I think using cable ties is a poor practice since nylon gets brittle and gives out much sooner than stainless steel wire.
4 people found this helpful. Do you?Thank Mark Watland
Marion Fisher
Posted November 3 2016
Well written, Jessica.

I learnt to achor confidently from an article in PBO some time ago. You sail or motor the anticipated swing circle once youve identified the centre, checking depth and swing. Finish the circle at the point of wind direction, drop anchor and drift back. The anchor grips and burrows ending very close to the centre. Mark and monitor and feel free to try again if it doesnt work the first time.
4 people found this helpful. Do you?Thank Marion Fisher

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