Like politics and religion, discussions about anchors tend to create polarising opinions between sailors.
But I do like a bit of a debate (and I love people who are passionate and have opinions even if they are different to my own), so please feel free to stick your oar in so to speak and let me know what your favourite anchor is in the comments below.
Anchoring requires a bit of practice to get the hang of, and for the Ocean Yachtmaster exam, you need to know a bit about it.
Types of Anchor
There are lots of different shapes and sizes of anchors. From the traditional shape that you might see on a sailors tattoo, through to the newer generation plough type anchors.
Wildwood used to have a Danforth anchor. But when it got too rusty I upgraded it to a new Rocna anchor, which we have been really pleased with. We have been anchored in some pretty hairy conditions, and it has never dragged (so far). We have got a Danforth anchor as our spare. It lays flat and so it is easy to stow in the sail locker.
You need to select an anchor that is going to work for the weight of your boat. Wildwood weighs about three tonnes, and we have got a 10kg anchor. Unfortunately for Andrew we do not have an anchor windlass (winch to pull the anchor up) so he gets pretty fit over the summer pulling up 10kg of anchor and chain by hand… The anchor manufacturers have got a sizing guide based on the length and weight of your boat. People who are cruising full time and anchoring a lot, often choose to go up a size if your bow roller and windlass can handle it.
To the anchor you need to add chain. The amount of chain you have is going to be dependent on the depth of water you usually anchor in, how much space you have in your anchor locker and whether you have a windlass or an Andrew to pull it all back up again. On Wildwood we have got 10m of 10mm shortlink chain, and then an anchor rode (line) of about 60m attached to that. Cruising yachts are more likely to have 50-100m of chain.
The chain can be attached to the anchor with a shackle. Make sure you mouse the end of the shackle pin so that it can’t inadvertently come undone… (like my mooring shackle did earlier this year – grrrr!)
It is recommended that you attach the end of the anchor chain to a piece of lashing and then attach that to the fitting on the boat. That way if you need to cut the anchor free in an emergency, you can just use a knife. Keep a spare buoy/float on a long piece of line with a snap shackle on the end so you can throw that overboard with the chain and then hopefully retrieve it later on.
The weight of the chain helps to keep the anchor laying flat on the sea floor. When it is being pulled horizontally along it sets deeper in to the water. If you don’t have enough chain then the angle of pull changes. If the anchor is pulled from above it pops out (which is handy when you want to leave, but not so good if you are fast asleep)
If you have all chain, then you also need a snubber. This is a length of stretchy line – around 5-10m long. You attach one end securely to the boat and the other end to the anchor chain. Let out the chain so that the stretchy line takes the load. This means that any shock from wind gusts will be absorbed by the stretchy line, instead of snatching on the non-stretchy chain (and potentially dislodging your anchor).
So now you have got all the key ingredients for anchoring, but before you go and drop the pick over the side there are a few more things you need to learn.
Choosing an Anchorage
So how do you know where to anchor? A cruising guide is a good place to start, along with your chart. Navionics has an option for people to add their anchorages and notes to the charts and these can have good tips as well. You will want to take in to account the composition of the seabed – sand, mud etc, the weather conditions, the forecast for the next 24 hours, and any current. Make sure you aren’t anchoring on any underwater cables (which will be indicated on the chart) and that you are well away from any shipping channels, entries and exits to piers, marinas or boat ramps etc.
It is very important to check the depth of the anchorage and also the height of the tide, as this is going to be critical to firstly ensure that it is going to be deep enough for your boat float when the tide goes out, and how much anchor chain you are going to have to use.
Check the cruising guide or charts for any hazards. Not all the rocks are charted, so it pays to have someone on the bow spotting if you are unsure.
Make sure you leave plenty of swing room, checking that there aren’t any hazards in the area you could potentially swing in to if the wind or current changes, and leave plenty of space for the other boats in the bay. A sure way to annoy another sailor is to anchor too close by, particularly if there is heaps of room.
In New Caledonia last year we saw a charter boat anchor right in between two mooring buoys. In this particular area you were supposed to pick up a mooring to avoid damaging the coral with your anchor. Along came another boat who wanted to pick up one of the moorings, but there wasn’t enough room. A heated discussion ensued, and eventually the charter boat pulled up his anchor and went on one of the moorings and the other boat picked up the other one. Lesson = don’t be a dick, and if someone anchors too close, then you might like to politely suggest and perhaps offer to help them anchor somewhere else. Better that than having to fend them off in the middle of the night.
Dropping the Anchor
Once you have scoped out your position, you are ready to drop the anchor. It is poor form to yell and scream at one another, be aware that while you won’t be able to hear each other, everyone else in the anchorage will (and they will all be watching), so it is a good idea to have a plan in place and a few hand signals sorted before one of you departs for the bow. Some people swear by headsets or walkie talkie’s to communicate if you have got a particularly long boat.
You can get an Anchor Watch app on your phone, and some GPS units have them too. This will sound an alarm to tell you if your anchor starts to drag. Be ready to press the button on the app or GPS as you lower the anchor. Perhaps drop a pin on the spot on the GPS, and make a note of that in your log book then if you do need to ditch your anchor, or want to come back and anchor in the same spot again next time, then you have got those details recorded.
Approach the spot where you are going to drop with your bow pointing in to the wind or current – whichever is stronger. You can usually tell this easily by the way all the other boats are sitting. When you are stationary you can start to lower the anchor and either drift slowly back with the wind, or engage reverse. The plan is to get the anchor to the bottom and then all the chain laying out nice and flat on the seabed.
Most boats have some system for measuring how much chain has gone out by way of markers, or different colour paint on the chain. The person on the bow should be counting out how many metres go out until you reach the desired amount of chain.
How much Rode?
The most critical factor in how successful your anchoring is going to be is how much chain/rode you deploy. First of all you need to know the depth of the water – does your depth sounder read from the bottom of the keel like mine does?
So say my depth sounder reads 5m, and my boat draws 2m (the distance from the waterline to the bottom of the keel) and then the bow roller is 1m above that – 5+2+1 = 8m
If it is low tide, and there is a 1m tidal range in the area I am anchoring in, then I will want to add that as well – giving us a starting figure of 9m.
The absolute minimum amount of rode you should deploy is 3:1 – meaning 3 x the depth or in our case 3 x 9m = 21m of rode.
The recommended scope is 7:1 – so in our case 63m of rode.
If it is forecast to be particularly windy then if you have the swing room you could go up to 10:1 = so 90m of rode deployed.
This is all to do with the catenary effect – or the angle of pull on the anchor. The more rode you have out the better the angle of horizontal pull on the anchor – which digs it in as opposed to pulling it out.
Setting the Anchor
It isn’t quite time for that beer just yet! Now you need to set the anchor. So once you have paid out the required amount of rode, then you will want to gradually reverse to dig the anchor in. If you go too fast to start with then the anchor will skip across the top of the sand, so start slowly and then when you feel it ‘grab’, then increase the revs on the engine to give it a good test.
Take a bearing from something beside you – line up another boat with a point on the landscape behind, or use your compass to get a feel for whether you are moving or not. Set the swing area on your Anchor Watch app or alarm.
If the anchor doesn’t set, then pick it back up and go around and try again. Try to look cool while you are doing this as everyone will be watching you… no pressure 😉
Once you are set nice and firmly then you should also display your Anchor Ball, which is the day shape you hoist at the bow to show that you are at anchor. We don’t actually have one of these yet but in some places you can be fined for not showing it, and it also might be something you are questioned about by your insurance company if someone hits you while you are anchored.
If it is dark then you should also show an anchor light – which is an all round white light at the top of your mast. I have heard some people also hang another white light on the bow, as it can be difficult to see boats in the dark, especially when the only light is 20m up in the air.
In places like the Marlborough Sounds, the water gets really deep very quickly and it is difficult to pay out that much scope without having a huge swing room. So in instances like this we can tuck in very close to the land, and put lines ashore to stop ourselves from swinging. We also like rafting up with friends, and there is some more information here about putting together a good raft up.
Other things to consider
You should have at least one spare anchor, chain & warp set up and ready to go in the event of an emergency. Some people also have an anchor at the stern.
If you should run aground you can use an anchor to attempt to try and pull yourself off. Jump in the dinghy with the anchor and set it in the area of deeper water, and then try and pull the boat towards the anchor.
The best rope to have as an anchor warp is nylon as it is strong, stretchy and it doesn’t float. (Floating lines can become tangled in your propeller)
An anchor weight or kellet can be attached part way down the chain. This assists with the horizontal pull on the anchor chain and also reduces the swing circle of the boat. It also acts as a spring, stopping the shock loads on the anchor which can pull it free.
In Lin & Larry Pardy’s book “Capable Cruiser” they talk about anchoring as if it is going to blow 50kts – every time. Even if the forecast is favourable, think about what would happen if the wind should change overnight, or a storm was to develop. There is a whole chapter in that book about a storm that swept through an anchorage in Mexico a few years back. Many of the boats were wrecked on the beach in an unseasonable storm, and many skippers admitted that they were not prepared. It is well worth a read.
If the weather is forecast to be very bad, then you can also deploy two anchors in a variety of different configurations:
- V Configuration. – You can set two anchors from the bow 90º apart. Set one anchor first and then motor over to set the second. Beware that it is easy to get very tangled up if you swing around.
- Tandem anchoring – The primary anchor must have a special attachment point on the crown of the anchor to attach the secondary anchor to. Lower the secondary anchor and then the primary, and then set. It might be a good idea to attach a buoy to the secondary anchor so you know its location and to assist with retrieval
- Bahamian Mooring – setting two anchors from the bow 180º apart. You can set the first anchor and then row out the second one. A weight attached to the rope rode will stop it from tangling in the keel. This can reduce your swing room, but can also create a tangle. Check out this video by Paul & Sheryl from Distant Shores where they explain how to do a Bahamian Mooring.
- Bow & Stern Configuration – this holds your boat in one firm place. Handy if you are wanting to keep your bow turned in to the waves and avoid roll, bit if the wind changes to be on your beam then this could cause the anchors to drag.
- Mediterranean Mooring – this involves deploying an anchor from the bow and then reversing up to a dock.
Every boat will handle differently on anchor. Our friends from Sailing Mareda have made a riding sail made to stop their boat from ‘sailing’ on the mooring.
Some books to read about anchoring:
Also check out Distant Shores on YouTube – they have some great videos of anchoring techniques and tests they have done.
Please feel free to share your anchor wisdom with me. I love getting your comments. How much scope do you use? Have you ever dragged or had to ditch your anchor? What is your favourite anchor brand? Your shared experiences really helps with my study! Thanks for reading 🙂
5 thoughts on “Awesome Anchoring”
Oh, you’ve opened up a can of worms talking about the controversial subject of anchoring 🙂 We had a Rocna on our boat in NZ and it was one of the first things we bought for our new boat in the States. We sleep far more peacefully with our Rocna.
Pingback: Ocean Yachtmaster | Astrolabe Sailing
Pingback: Coastal Skipper | Astrolabe Sailing
Pingback: Awesome Apps for Sailors | Astrolabe Sailing
Pingback: RYA Offshore Yachtmaster | Astrolabe Sailing