Anchoring in a tight spot
Finding a suitable place to drop your hook can be easy in some anchorages and seriously challenging when things are tight. Not being prepared, or worse shouting and screaming during a botched manoeuvre, can provide great entertainment value to fellow boaters already anchored. Rest assured, they will be watching your every move. Anchoring is, after all, a spectator sport.
Let’s see what one can do to make it easy.
A bit of planning, particularly when it comes to a crowded anchorage, can make all the difference as to whether your entrance is elegant, or ‘interesting’.
Review your anchorage options before your cruise. Check the charts, guidebooks, and online resources for suitable places to stop overnight. What do the charts say about the bottom composition? Review the predicted weather conditions, taking wave action and storm potential into account. Check the tide table to be certain that the anchorage has enough water to accommodate your boat’s draft at low tide.
When you get there, it is advisable to cruise slowly through an anchorage to inspect it. Note how the charted depths and features relate to the actual physical appearance. Note how other boats have anchored. Is there a likely looking gap somewhere? There may be a reason that nobody has anchored in a particular location, like an unusually deep hole with sloping sides or a submerged rock. On the other hand, that may just be the perfect spot. If you cannot tell from what you see, don’t be afraid to ask your potential neighbours how much scope they have out or any other information that might help.
One quite foggy afternoon we entered Tinker’s Hole, a tiny anchorage near Iona in Scotland. Passing through the narrow entrance in poor visibility with a following swell left our nerves jangled. When we got in, it appeared that there was not enough room to turn a 20 footer, whatever about anchoring our 57 foot classic ketch. While discussing how to get back out, we slowly moved in. A gentleman on one of the anchored boats hailed us. He had clearly been watching us approach. We came alongside and he pointed to a spot indicating that if we anchored just astern and to starboard of the yacht ahead of his and then drop back we should be just fine – and so we were.
Boats will always move around while at anchor. This is called shear or yaw. Catamarans, mono-hulled sailboats, large vessels, powerboats, or flat bottom boats will all swing with very different characteristics. Some fin keeled boats yaw to the extreme while older, full keeled boats, may ride straight as an arrow into the wind or into the current. Take the time to observe the vessels nearby and try to anchor away from boats that move differently from yours. If there’s plenty of room, there’s no worry. It’s when the anchorage is crowded that this becomes an issue and boats can get closer together than one might like.
If the wind shifts, which it commonly does, then all the boats in the harbour will swing in the same direction, albeit with their own particular idiosyncrasies. Consequently, it is also good to know and match the other boats’ lengths of rode. If not, what appears to be a very orderly anchorage as in the illustration below, can rapidly become a tangled mess. This usually happens in the middle of the night in deteriorating conditions.
With the preceding taken into consideration, and having found a hole in the anchorage, you will ideally motor slowly to windward and drop your hook equidistant and just astern between two boats to windward – preferably of a similar type to yours. You will then aim at deploying the same amount (and type) of rode as they and the others in your vicinity.
It is also important to pay out your rode slowly as your boat backs. Keeping a little pressure on the rode will also help the anchor set. Never drop all your rode on top of the anchor.
Some anchors may take more distance to set than others. In this case, you may want to drop a little further upwind.
Never be shy about picking up and trying another spot if you end up somewhere you did not envision, or if it does not feel right. There is no shame in setting more than once; others will respect your seriousness.
Most people consider a 5:1 ratio (scope) rode/depth to be the minimum scope for safe anchoring under moderate conditions. We usually go for a 7:1 scope with our all chain rode, more if we are expecting stronger winds. More scope is always better.
When calculating the scope, the ‘depth’ is the height of the bow over the bottom, taking the tide height into consideration. Keep in mind that your depth sounder may be giving you the water depth under your keel. In this case you also need to add in the offset as well.
In a tight anchorage, as in our example in Tinker’s Hole, you may not be able to let out as much rode as you might like. In this case you will need to weigh your options and see what is best for you and your vessel. With the very settled conditions we experienced there, we decided that 3-1 should suffice. With our scoop type anchor down, we initially let out enough for a 5-1 scope, power set the anchor, and then brought the rode back in to a 3-1 ratio. With less rode, say at 2-1, even our scoop type anchor may have pulled out, while power setting or had there been an increase in wind speed.
To ensure that the wave action does not loosen your anchor’s hold on the bottom if you have an all-chain rode, you should use a long snubber to absorb any shock loads caused by wave action. A long stretchy rope (nylon) of sufficient diameter will do here. This will stretch in and out over the bow roller as waves pass under your boat.
Irrespective of what type of anchor you deploy, the holding power of your anchor is greatly reduced with any reduction in scope. If you have to drop anchor in a crowded anchorage with deep water on short scope, setting anchor watch may consequently be a wise option.
The Right Gear
No discussion on anchoring is complete without at least a mention of anchor tackle.
You will have noted that in the preceding illustration the chain is not bowed. In high wind situations, any rode, chain or rope, even with a heavy kellet or chum, will go bar taut. Catenary only applies to light wind situations, where it is least needed. When considering tackle selection, one must always go out from the worst case scenario – after all, your life is depending on it.
Having stated that, in consistent light wind conditions, using an all-chain rode or deploying a heavy kellet towards the bottom of an all rope rode will allow you to hang off your chain or kellet and work with a very short scope of rode. However, should conditions change in the night, which is when bad things always tend to happen, then you could find yourself in some serious trouble.
All anchors are not created equal. By their very design, some anchors are meant to plough, and others to drag, perhaps to minimise strain on the deck hardware. Given sufficient scope, the newer generation scoop type anchors dig deeper and hold better as the pull on the rode increases; this happens when you power set the anchor or when the wind increases. Scoop types are by and large also designed with larger blades and a greater angle between fluke and shank to facilitate this even better. In general, most of the new generation scoop anchors deliver superior holding at shorter scope than the older anchors can. Small wonder then, that whereas about 80% of Ocean Cruising Club members reported having a CQR as their bower just a few years ago, a more recent survey revealed that nearly 90% now have a scoop type as their primary.
Setting Two Anchors
In very tight anchorages, or if anchoring in close proximity of a permanent mooring field, you may wish to consider setting two anchors from the bow, in opposite directions. This is known as a Bahamian Moor. This method of anchoring completely minimizes your boat’s swing radius. Permanent moorings tend to have very heavy weights or other devices to firmly attach to the sea bed. They may thus have very short scope, often verging on less than 2-1. However anchoring in or very close to a mooring field is generally not recommended, as there is often legacy tackle littering the sea bed that may snag your anchor. If considering using a Bahamian Moor in a tight anchorage, ensure that the other boats have done the same. If not, they might most assuredly swing into yours.
If the anchorage is ‘tight’ due to lack of space, being on the edge of a channel or something similar, you might also consider a bow and stern configuration. This will maintain the position of your boat very tightly. Your boat will not swing into the channel, but it also will not swing with wind or current. This could potentially expose the stern to unintended forces; remember that a boat is designed to receive wave action from the bow and not from the stern.
In either of these two cases, you may begin by dropping and securely setting your primary anchor. You can then let out more than twice the necessary rode, while backing down to where you would like to position the secondary anchor, deploy this and bring in the primary rode, while paying out the secondary. To set the latter, gently motor forward and then adjust both rodes to allow for the tide, etc.
For use as a secondary anchor, we keep a lightweight aluminium fluke anchor (Fortress) on board. Although quite large when assembled, it can easily be loaded into our dinghy and deployed without having to try to manoeuvre our (big) boat. We have a full length of nylon rope rode for our secondary anchor and can let out as much as we please to set it before winching it back in to position our boat where we have chosen.
At home, social etiquette is something one learns from one’s parents. For example, most people grow up learning to eat at a table, each culture in its own way. On the other hand, not everyone grows up boating. Therefore, it is hard for most people to have a finer sense of behavioral dos and don’ts on the water. Unless you are a Robinson Crusoe anchored off a deserted island on your own, there are some things we all need to know.
The cardinal rule of anchoring etiquette is quite simple:
The first boat anchored sets the precedent.
This ‘rule’ is actually written into Admiralty case law:
“A vessel shall be found at fault if it ... anchors so
close to another vessel as to foul her when swinging ... (and/or) fails to
shift anchorage when dragging dangerously close to another anchored vessel.
Furthermore, the vessel that anchored first shall warn the one who anchored
last that the berth chosen will foul the former’s berth.”
The use of an anchorage is on a first come, first served basis. The first boat has the right to anchor whichever way they please, putting out one or two anchors, in whatever configuration with as much scope as they deem appropriate. Everyone else is obligated to avoid interfering with any boat there before them.
This, of course, makes life difficult when you come into a crowded anchorage. Which boat sets the precedent? As far as your boat is concerned, they all do. The onus on you is to not foul any of the others.
If you are uncertain as to how the others in the anchorage before you have anchored, ask them. We have never met anyone not willing to share. If you are uncertain as to how to proceed, ask again. As happened to us in Tinker’s Hole, the advice may indeed be good. If you are still unhappy, you can always move on; assuming that is an option. Otherwise, follow the advice and assign an anchor watch to keep an eye on things to ensure the boat and crew will be safe.
Needless to say, whether you are the first to arrive or the last does not matter if your anchor drags. That makes yours the burdened vessel in the eyes of the law and you must keep clear of all other boats. Everyone may drag anchor at one time or another. It is how you handle the situation that makes the difference.
This article is adapted from the best-selling book “Happy Hooking - The Art of Anchoring” - now in its third edition! It covers every aspect of anchors and anchoring in a fun and easy to read format with lots of photos and illustrations.
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