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| About Those Practical Sailor Anchor Tests (and Anchor Tests in General)
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March 13, 2002
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This note arrived from Kath Sercu, asking for follow-up about anchor sizing and what was wrong with Practical Sailor's tests.
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In Anchor Sizing and Relative Holding Power Ratings, Febuary 22, 2002, you wrote:
Several publications have gone to great effort to develop
relative holding power ratings for various anchor designs.
At first glance, this seems like a reasonable thing to do, but
in reality their findings are of only limited usefulness. In the
case of Practical Sailor's tests the findings are just plain
wrong, because their test parameters were deeply flawed.
I am interested in what you consider to be the flaws in Practical Sailor's tests of anchors. I am considering purchasing of an additional anchor and think the review offered a reasonable comparison. If I missed something I
would like to find out before I buy the anchor.
Thanks for sharing your insight and experience.
Kath
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Response
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I had extensive correspondence with Practical Sailor when their anchor tests were published, but it was some time ago and my copies are buried somewhere in the Robert Hale & Co. archives. So I'm working from memory here.
My first criticism was that in the case of Bruce (I know Bruce very, very well), they used a 22-pound anchor when it should have been a 33-pounder to be similar to the 35-pound CQR they used. It would be like comparing the load capability of Brand A's half-ton pickup truck against Brand B's three-quarter ton pickup and concluding that the three-quarter ton truck carries more. Well, of course it does. But you haven't really learned anything.
Practical Sailor defended its anchor selections by saying that they contacted each of the various suppliers and went with the suppliers' recommendations. The problem was that their hypothetical test boat was at the crossover point between two sizes. CQR suggested the larger size, Bruce, the smaller size. At that point the test was compromised. It makes no difference why it was compromised, or how defensible their position was. The two anchors simply were not comparable. I don't know my Danforth style anchor sizing very well, so I can't comment on their selections there. But in the case of Bruce and CQR, they began their elaborate tests with garbage in.
Next, they tested on (if I recall correctly) 7:1 scope. This is understandable; Chapman's recommends 7:1, and they could get in trouble for even hinting that boats might anchor on less than 7:1. Unfortunately, regardless of what Chapman's recommends, in Northwest waters boats don't anchor on 7:1 scope. They usually anchor on about 3:1, maybe 4:1 if they can find room. Thus they tested for a condition that does not square with actual practice. More garbage in.
This is the problem with all anchor tests. To make a test you eliminate variables in the hopes of finding valid comparisons. Anchoring, however, is made up of nothing but variables. I am reminded of a supposedly French comment I read many years ago: "Yes, it works in practice, but does it work in THEORY?" Anchor tests focus on theory. Actual anchoring is strictly a practical exercise.
Fortunately, a valid anchor test does exist. It's the anchors themselves, mounted on the bows of boats, used by a wide variety of mariners in a wide variety of anchoring conditions. You find the good people, study their anchoring systems, ask what they like and dislike about their systems, and make a judgment. It is not necessary to conduct extensive (and exhausting!) pull tests so the results can be applied to the real world. All that's needed is to go into the real world and get the information.
And as the February 22 posting indicates, the relative holding power of various anchors is almost meaningless. You pick the design you like, find the size that will hold your boat safely, and the job is done.
To me, the important criteria for anchor selection are strength, so the anchor doesn't bend or break; setting ability in a wide variety of bottoms; veering capability, so the boat can swing in circles and remain anchored; short scope performance for deep, crowded or tight anchorages; and breakout forces. The size requirements for different boats are well known and easily learned for all the popular anchor designs. The relative holding power of different anchor designs is meaningless.
Enough of my soapbox. I hope this helps.
--Bob Hale
P.S. Despite my criticism of Practical Sailor's anchor tests, I am still a big fan of Practical Sailor. I have subscribed for years, and read every issue the day it arrives. I've had a number of excellent correspondences with Dan Spurr, the former editor, and I'm a huge fan of Doug Logan, the present editor. Doug Logan is a terrific writer. I wish I could write as well.
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