Extracted from "Littoral Drift" by E. Seling 1994
You can be sure that effective anchoring is a prime concern of mine. I am by nature a technical sort with a compulsion to understand and systematize the things about me. Long conversations with a good friend and former chief engineer for a major anchor producer gave me access to a lot of information on different anchor types and insights into their design. With this information and several years of experience I have developed anchoring routines which work well for us, well enough that I can rest (yes, even sleep!) in strong winds without undue concern for Moonshadow's safety. Of course one of the beauties of sailing is that one is always learning, but if I were to give a course right now on the art of anchoring along the ICW here is how it would go:
First you must have good gear. The waterway bottom is primarily mud of varying degrees of hardness. Given a chance most anchors do pretty well. Plow anchors get good reviews from seasoned cruisers, they are useful general purpose anchors. The Danforth fluke-style anchor also has its adherents but many find it occasionally difficult to set. Fortress anchors are an interesting variation on the Danforth. The Bruce anchor is becoming increasingly popular and its devotees are adamant about its superiority but there is a bit of religious zeal in their stance that may not stand up to reality. Owners of character boats usually have a Fisherman anchor stowed away somewhere but few are given daily use; that's just as well. My favorite is the Danforth Deepset plow. This is a lightweight plow, designed for deep penetration that holds well in all waterway bottoms. A cruising boat should carry at least two anchors and preferably three of two different styles. Moonshadow carries 2 Deepset Plows, 1 Danforth standard, 1 Danforth Deepset fluke anchor, and 1 Danforth VSB (a single purpose soft mud anchor). Whichever anchors are chosen it is essential that they be sized to your boat. An anchor suited for a 22 footer just isn't going to hold a heavy 40 ft. cruiser. Use manufacturers recommendations to help select an anchor but throw in a "personal anxiety level" safety factor to allow for the occasional poor bottom and marginal protection. Going up one anchor size is usually a good idea for a 'storm' anchor, a 'working anchor' need not be so heavy. And don't forget a good length of chain, essential in all but a few conditions. If you think that you can't haul up heavy anchor tackle then consider the purchase of a good quality anchor windlass. The security of a big anchor down in heavy winds will more than make up for its cost. Some of the waterway anchorages are a bit on the remote side, that's their charm, and you'll want to be confident in your ability it stay where you've chosen.
That brings us to choosing a good spot to anchor. The various cruising guides are the first sources of waterway anchorage information. They indicate the tried and true spots for a nights rest and will sometimes indicate inadequacies. Some sections of the waterway have few anchorages and the guides will list them all, but in other parts, notably Georgia and the Carolinas the anchorages are numerous and the chart will be your guide. First, listen to the latest weather forecast for expected conditions noting especially any predicted wind shifts. What is a good anchorage in one wind may become an uncomfortable or even untenable one if winds shift to another direction. Knowing the weather you should be able to look at the chart and pick a spot most suitable for both present and predicted conditions. My first principle of anchoring is "never have more water to windward than to leeward." Like all good rules this one has many exceptions but in general anchor where there is a shore close to windward to give protection from the wind and sea and where there room to leeward to drag if the hook doesn't perform as expected. With a little bit of practice at chart reading you will quickly find spots which satisfy these requirements. Note the chart scale - a cozy nook could actually be a river a mile wide if you've not got a good idea of the distances represented. Inspect the surrounding terrain. The chart shows low marsh as olive green which offers little or no protection from the wind, but, often more important, will prevent any sea from forming. Higher, often wooded, land is shown in a yellow-ocher tint. This offers good protection from both the wind and sea but on a calm buggy night you might not want to be in its lee. We have learned that the no-see-ums especially like the thick blood of people adapted to cold winters!
The chart gives clues to the holding quality of the bottom. Areas marked "M" (mud) will offer good holding as will "sft" (soft) while "hrd" (hard) bottoms may not allow the anchor to penetrate. Deep portions of a river especially near tight bends where currents are often swift usually have a hard, scoured bottom, the straighter shallower portions will have a softer bottom, better for holding. Basins which have been dredged out and then allowed to silt in will often have very soft bottoms and provide extremely poor holding. Mile Hammock Bay on the ICW is a good example.
Special consideration should be given to the current which will be found in many of the creeks and rivers. In general the more area a river drains the greater the current you will have to contend with. Deep areas of a river as well as bends tend to have more current than straight shallow areas. (This is what causes the difference in holding ground referred to above.) Short tributaries usually have less current. With little wind, anchoring in current is not a problem but when more wind is expected avoid anchoring where it will blow against the current. Such conditions can raise a very uncomfortable chop. Your vessel may swing and sheer about and it is possible for the anchor rode to foul on your keel causing chafe and possible loss. Why repeat the mistakes I made at Por Le Bear. The best strategy is to choose a spot where the wind will blow at right angles to the tidal current. This is easy in the winding creeks of the southeastern coastal 'low country'. When this is not possible there are anchoring techniques to help. (More on that later.)
You will also want to give some thought to traffic. Commercial vessels frequently use the waterway at night making many attractive 'swellings' on the ICW unsuitable for overnight use. Anchoring in narrow channels used by fishing vessels should also be avoided. Even with an anchor light up (make sure you have a bright and reliable one) a boat is difficult to see at night and the possibility of collision does exist. Best to look for a spot out of the channel.
One final word about selecting anchorages. The best place is not necessarily where other boats are. Frequently an unsuitable anchorage is crowded while another better one nearby goes unused. Everyone assumed the 'other guy' knew what he was doing. While new friendships can be fun you don't want to meet people in the middle of the night when the wind comes up from an unexpected quarter and you discover the fellow along side had out more line than necessary or the holding ground is poor and everyone starts doing 'bumper car' at 2 a.m.. Trust your own judgment and remember that safety does not always come in numbers.
Once you've selected (and arrived at) the best spot getting the anchor down and into a patch of ICW mud is pretty much the same as any other place. Be sure to lower the anchor slowly and pay out line as the boat is powered astern. Watch the shore or landmarks abeam of you to be sure the boat is actually moving over the bottom. Let out adequate scope for the depth of water and conditions, five times the depth at high tide is frequently used but three is often sufficient in light winds and seven may be required in heavy winds. It is a good idea to have your anchor rode marked at intervals so you can judge this. To ensure that others will have room to swing do not let out more line than necessary. It's definitely bad anchorage manners to use up an excessive amount of room with scope of eight or ten to one. After letting out your rode snub the line around the forecleat and back down on the anchor, gently at first, then with more throttle, to set it. Once again use landmarks abeam to judge whether the anchor is holding. If it refuses to set haul it all the way to the surface to make sure it's not fouled and try again. If two attempts don't do it maybe something is wrong. Did you let out sufficient scope? Did you set the anchor gently at first? It may be that the bottom is unsuitable for one type of anchor and another will work better. Some of the mud in the waterway is very oozy, slimy stuff and a Danforth-style anchor with the usual eight feet or so of chain may refuse to set. This is because the flukes 'float' on top of the mud when the anchor settles on the bottom and the chain pulls the shank into the thin mud down lower than the level of the flukes. In this position the anchor skates along, refusing to set. One solution is to remove the chain. This may be counter to all you've heard but it works. The anchor will then readily set and hold quite well. (The line may be susceptible to chafe though and so this technique is not for bottoms with a lot of trash, rocks, or coral.) In really stubborn cases it may be best to let out 2 to one scope and then give the rode a few quick jerks. This will get the shank and flukes into the proper relationship and the anchor should start to bury, then you can let out all the scope. This "fishing" with the anchor will not work with chain on the anchor and you look kind of stupid doing it but it's worth it if it works. I know of several places where no other technique will get a Danforth-style anchor to set, a fact which has caused many sailors to distrust or abandon an otherwise good anchor. A conventional plow in oozy mud conditions will set OK but it's ultimate holding power may be low. In such conditions the Danforth Deepset plow is a good alternative and the VSB or a Fortress set at "mud angle" are an excellent choice.
If you are in a lot of current and your swinging room is limited it may be wise to set a second anchor. Let your boat drift back in the current until you have out a little more than twice the necessary scope, drop your second anchor and then take back in on the first rode. Presto, you have two anchors out, one up current and one down both with the proper amount of scope: the standard Bahamian moor. If the wind is blowing against the tide as you do this you may have to help things out a bit with the engine to get your second anchor in the right position.
In settled weather, as an alternative to using two anchors, you might want to try using an anchor sentinel. This is a lead weight of about ten to fifteen pounds attached to a block or a rider which is lowered down the anchor rode. You may easily make up your own rig with a block and a downrigger fishing weight or buy one ready-made from a chandler. Since Por Le Bear I use my anchor sentinel ninety percent of the time when anchored in current and recommend it highly. It performs several useful functions. First of all with the weight lowered all the way to the bottom Moonshadow swings about it rather than about the anchor as the tide takes the boat back and forth. In light to moderate winds this reduces my swinging room dramatically, nearly as much as having two anchors down. Should the wind increase the sentinel will come up off the bottom and then I have the proper amount of scope out. Additionally, in wind against the tide conditions, the sentinel will hold the rode away from the keel and prevent fouling and chafe. Be sure to lower it to the bottom to get its full effect (this is not possible in strong winds when you should just put out some 10 feet or so. For greatest security you can moor with two anchors with a sentinel on each to keep the slack rode away from your keel. One sentinel can be attached to two rodes with a smooth shackle or carribiner. Should you remain anchored more than a few tidal cycles take care that the rodes do not twist too many times. Allowing this to happen makes retrieving your gear a long and laborious process.
So that's all my secrets, simple really. Many people look on anchoring as a mystical art: the anchor plunges to the bottom and weird and unearthly forces conspire to make it set or drag. In reality its just a matter of the right tools and a little technique.
The BEST treatment of anchoring theory, selection and use is found in:
"Modern Seamanship" by Don Dodds, Lyons & Burford, Publishers, 1995
(31 West 21st St. NY, NY, 10010)