Types Of Anchors

Anchoring safely - an experienced cruiser's techniques

My wife and I live at anchor at least half our lives, we only pay for a marina or mooring when we stop to earn money.  My main motivation for paying for a berth then is not so much that I am worried about Freelife dragging in my absence (although if a gale was forecast I would be reluctant to go to work)  but I am concerned that another boat in the anchorage will drag its anchor and wrap around my yacht. Over the last decade there seems to have been a general decline in anchoring skills.  I’m not sure if it’s because of the increase in marinas and hire moorings, the increasing use of lightweight anchors, modern yacht design or something else.  But these days if I am in a crowded anchorage and the wind gets up, a greater percentage of boats in the anchorage seem to drag. We get hit by another boat dragging its anchor on average once per year by everything from yachts to trawlers. We now anchor defensively, i.e. if it’s going to blow we forgo the sheltered corner of the anchorage and move to the windward end so others drag away from us.  We move if someone anchors up wind and I don’t like the look of how they have anchored.  However, we still get hit occasionally.  Conversely, if I see someone who I know is good at anchoring I will often anchor downwind of them, using them as a barrier. Most of what I learned about anchoring I learned from other sailors who seemed to be doing it well with the odd bit of useful info gleaned from reading one of the many anchor tests that appear regularly in nautical publications.  We had to learn as I am too cheap to pay for a berth most of the time.  We learned to sail in the South Island of New Zealand, where you can get storm force winds whipping through an anchorage at night. Whilst you may get protection from the sea there is often none from the wind. Anchoring is not rocket science, it can be easily learned.  I think the problem for a lot of people is not knowing what to believe from the array of anchor tests, recommendations and claims.  I won’t recommend any particular type of anchor.  Personally I have a variety on board, some work better in different circumstances.  I just want to share some general principles that should, when put into practice, give those who are having a lousy night’s sleep more confidence.  You can get to a stage where you don’t have to wake up or maintain an anchor watch, unless things get really bad and by then you can’t sleep anyway. You can leave your boat at anchor while you go on a daytrip with confidence. First of all any boat can drag, it doesn’t matter how good your skills are.  Bear that in mind and don’t (as was the case with one yacht I rescued) leave your half million dollar yacht on an inadequate, poorly deployed anchor in Tonga, unattended while you fly back to New Zealand for three months.  Also, don’t expect your anchor to hold for very long if you anchor on a lee shore amongst 2m breaking swells (another real incident that caused the loss of the vessel). Anchoring is all about risk minimisation.  There is some risk you have to accept in everything we do but you can get it down to a level where the risk is relatively small and conditions have to be quite bad before you start to lose sleep.  Early in our yachting lives I went for the odd drag in an anchorage and that spurred me to study it in some detail and whilst the potential always exists it is now fairly infrequent.  Despite living at least half our lives on the hook and anchoring everywhere from the roaring 40s to the tropics in the last ten years, we haven’t dragged.  That doesn’t mean that I have the attitude that it will never happen, just that I have reduced the risk so that it hasn’t happened in 10 years. Even if your arms aren’t as short or your pockets not as deep as my own, there are good reasons, other than saving money, to learn good anchoring techniques. For example, it widens the number of available anchorages, lowers the skipper’s stress level and it might save your boat if it’s going to blow and there are no marinas or hire moorings in the vicinity.  I have never found a harbour that I can’t poke myself in somewhere and often while my friends are spending $25 per day on a hire mooring, I get to spend that on fish and chips and ice creams. First of all select your anchorage with care, if there is no wind and a flat sea and it looks like continuing, you can probably anchor anywhere safely, so long as it’s not a high traffic area and you are likely to get run down.  Have a good look at the chart for things like a foul bottom that might make getting the hook back up difficult.  If you can avoid strong currents do so.  Watch out for submarine cables. Look at the bottom type; mud and sand would be my preferences before heavy weed or gravel. Don’t overlook local knowledge and cruising guides (we use Alan Lucas’s books all the time), but always assess the source of the information as some sailors are more knowledgable than others. Many times we have had locals tell us “you can’t anchor there everyone drags there”, in an anchorage with an apparently good bottom in a protected situation. You will need to make your own assessment of the information. Charts and cruising guides are normally accurate, but if they seem at odds with what you are being told at the local waterfront bar, have a look and see if anyone else is anchored there. A local live-aboard on the hook, who doesn’t own part of the marina, might be a good person to ask. Or just try it and see if the anchor seems to set.  You might lose the odd anchor to a foul bottom but I haven’t lost a hook yet, touch wood. Ok, so that covers where to anchor, now the how.  When it comes to choosing an anchor type, by all means take advantage of written material on how different anchors perform in different situations, but if the test is conducted by someone who sells anchors I would take the info with a big pinch of salt.  Invariably, after extensive and impressive sounding tests the anchor they sell just happens to be the best. Also beware of recommendations by yachties who live mostly in a marina and perhaps cruise at a lattitude where they think heavy weather is 30 knots, recommending the latest lightweight, super-duper, space-age looking hook. If I am going to accept anecdotal evidence of an anchor’s performance I will give it more weight if the person offering the advice has spent a long period of time living at anchor in a variety of locations and conditions. First of all, size matters. When an anchor gets force applied to it that reaches the limit of that anchor's ability to hold in that particular sea bed, it first starts to plough slowly through the sea bed and if more force is applied it will drag; the point at which this happens changes according to weight and surface area. All other factors being the same, the heavier, larger anchor of the same type, will stand more force before it drags.  As a general rule of thumb I try and go at least two sizes bigger than the anchor manufacturer recommends for my type and displacement of yacht. Obviously we can’t all have 200kg ship anchors hanging off the bow roller, but when setting up your windlass, chain and rode package keep the principle that ‘size matters’ in mind.  Regardless of the type of anchor, get the biggest version of it that you can stow, deploy and recover. The obvious exception to this is the kedge anchor which must be small enough to handle from a dinghy if you run aground. Second is type, the following are the ones I have experience with. No doubt there are numerous other good anchors around. Most anchors hold well in sand and mud, which fortunately is the most common bottom type, but don’t put all your eggs in one basket.  When it comes to rock, the good old fisherman anchor sometimes called the ‘yachtsman anchor’ is great. We spent two months lying to it in Port Vila, Vanuatu, through some very snotty weather. Port Vila has notoriously poor holding with most opting to hire moorings when the wind gets up as the bottom has a thin layer of sand over rock.  I dropped the fisherman down and jumped in with my snorkel, found a nearby hole in a rock that I dropped a fluke of the fisherman into and we weren’t going anywhere. I did have to dive back in to take it out by hand when we wanted to leave though. Then there is the Danforth type with their large flukes giving good holding in relation to their size. These have a peculiarity in that they may not reset as well as the claws and ploughs if the direction of pull is reversed, i.e. if the wind or current reverses direction.  Most of the time they will cope ok but they are a bit more prone to pulling out if the direction of pull is reversed. Sometimes the chain can foul the anchor and drag it sideways across the bottom, not allowing it to reset. In the right place the Danforth can be wonderful, if moored Mediterranean style, stern to a wall, the direction of pull doesn’t change, or in a river anchored bow and stern so that you don’t swing. We have two on board, a smaller one which we use as a kedging anchor. It sits on the pushpit ready to throw in the dinghy and row out if we touch bottom on a falling tide. We just drop it in the direction of deeper water, hook it to the spinnaker halyard and use a mast winch to pull the top of the mast towards the anchor. As the yacht heels the draft is reduced and the yacht slides towards the anchor and into deeper water. We also have a large Danforth which doesn’t see service often, but with its sharp points and large surface area it will often set in a hard-packed bottom when claws and ploughs just drag along the surface. A fisherman might penetrate but lacks the surface area to hold well, especially if the hard-packed bottom is a thin crust with softer ground underneath. You may not use it often but when you are tired, cold and just want to flop into bed and the others are refusing to set, you will be glad you have been carrying it around. Just remember get the heaviest versions you can handle (if you can stow them on the bow rollers permanently, even better).  We hedge our bets and have one of each permanently on the bow, which brings me to another point. Many first time cruisers will set off with one anchor of a particular type. As they gain more experience they learn that you need several anchors on-board, preferably of different types, so you can safely anchor in different conditions and in different bottoms. Third and most important is how to set your anchor and the following should apply regardless of what type of anchor you have. First let's deal with scope. The old rule of thumb used to be three times the depth of water you are anchoring in at high tide. Research has shown that regardless of what type of anchor you are using or bottom type, that going from a three to one scope to a six to one scope doubles the holding power of the anchor before it started to drag. Interestingly, when the scope was increased to ten to one you only got a further ten percent increase in holding and beyond ten to one very little benefit from increased scope. Obviously it would not be practical to set yourself up for a storm if you are only stopping for lunch. Our rule of thumb for overnight anchoring is that if the forecast is for twenty knots of wind or less, we put down one anchor. If the forecast is for any more than 20 knots or if we are planning to stay at the anchorage more than a few days, we put down two anchors, almost always in tandem on a single rode. When we have picked our spot and done a circuit of my predicted swinging area looking at the depths, I will head the boat into wind or current, whichever is the stronger. Look at other moored/anchored boats to get a good indication of what way you might lie. Then drop your first hook - don’t let the anchor hit the bottom and heap a big pile of chain on top as this might foul the anchor. You can generally feel when the anchor has hit the bottom (the chain normally runs out slower). Once the anchor is down, slowly veer rode up to the required scope as the boat drifts back, if no wind or current you might have to engage reverse to lay the rode out. Once you have your six to one scope, secure the anchor rode. I normally put a short piece of braid, via a clove hitch, onto the chain and take the strain onto the Sampson post (or strong cleat), as most capstans were not designed for snubbing loads. Then you engage reverse, first at idle then gradually build revs. Line up something as a transit on the shore abeam of you and see if you are moving, also touch the rode with your hand or foot and you can feel what the anchor is doing. The vibration travels up the anchor rode when it is under tension and you will find you can feel if the anchor is dragging and even tell what it is dragging through, i.e. bumping over rock or sliding over mud. If your partner is on the helm and you are on the foredeck, as is common with cruising couples, try not to shout things like “reverse” and “more revs”. You might only be trying to compete with the wind and engine noise and you end up sounding like Captain Bligh.  You don’t want to suffer the same fate as him so work out some simple hand signals. We use: thumb down = engage reverse, point forwards = engage drive, one raised finger = idle revs, two fingers = medium revs, three fingers = high revs, closed fist = neutral, finger across throat = shut engine down. Don’t get frustrated when you’ve tried three times and it’s still dragging over the bottom. Generally that means it’s time to try another type of anchor. That’s why a variety on board is good. I haven’t found an anchorage yet where I can’t get one of my hooks to hold.  Most of the time your hook will set first time, but just occasionally you have to do a bit more work to make yourself secure. Then, if you are only putting the one anchor down it’s time to apply the snubber.  The snubber is a piece of nylon rope that does a number of things. First is shock absorption - being stretchy, when a gust hits the yacht and she pulls up on the anchor rode, it softens the pull applied to the anchor, making it less of a jerk (also making it more comfortable inside).  If you have a nylon rope rode it will provide the shock absorption anyway.

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When it comes to ships, anchoring is an important aspect that should be taken seriously. In the absence of anchors, ships would continuously adrift leading to huge wastage of resources like energy and also increase chances of accidents. In order to avoid these problems, mooring anchors are used to enable the ship to halt effectively whenever required in the port or harbours and if required, even in the middle of the ocean or the sea.

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