I’m frequently asked what my opinion is of a given anchor, often of a new pattern.
And over the years I have developed a pat answer:
Sorry, I don’t opine on anchors unless I, or people I know well and trust, have used the anchor several hundred times in many different places over a period of several years.
At this point, almost invariably, the questioner adds that his or her interest was provoked by the anchor in question’s great performance in a test.
That would seem logical…except for the fact that most, maybe all, anchor tests are flawed and therefore should not be used, at least not in isolation, to determine what anchor we voyagers should use to keep our boats and loved ones safe.
My professional career started with the test and evaluation of some very expensive stuff, satellites and the rockets to launch them. Test cost often reached 50% of the developmental cost. Unfortunately, some of the test ethic we applied in those days is no longer affordable. We designed tests along two axes — test to destruction and test to develop the perimeters of a performance envelope.
Most, OK all, of the anchor test results I have seen in 41 years of sailing have conflated the two testing regimes and have resulted in three fallacies, intended or not. Fallacy 1 = test conditions accurately reflect operational use. Fallacy 2 = enough testing has been done to produce statistically significant results. Fallacy 3 = test designs capture environmental variability. These fallacies are either derivative of tester bias or external ($$$) constraints on test design, execution, and interpretation.
Your case about soft mud is a good example. What is soft mud? What is the statistical distribution of particle sizes, what is the ratio of water to solids, are there lubricious deposits in the mud, etc, etc… We scooped up two equal measures of mud from a dive site several years ago (in preparation for hiding a weapon for recovery divers to search for). The first can weighed 20% more than the second can. The samples had been taken 2 feet apart. Overall, we found a 30% variability across the 1/2 hectare site. The site survey chart was labelled Sft Md over about 3 hectare.
We have come to rely on our SPADE a great deal more than any other anchor we have had, but we still won’t trust it during transitional events. We still set anchor watches and use anchor drag tools.
Hi Chris,
Thanks very much for the clear and experienced engineer’s read on this.
Thanks, John,
Anecdotally, after one season of turtle grass in the Abacos we knew our anchor was destined for replacement on our return to the Chesapeake. Having anchored off Galesville, MD, we were later warned of the derecho heading for the DC area and had just enough time to run out more chain and add the second snubber. Winds were predicted to be 70 mph.
The first gust that hit us, registered 89 mph and nearby they saw 100 mph. The 70+ wind lasted for 15 minutes. We expected to be on the beach before it was all over, but amazingly the anchor, so irritatingly untrustworthy in the Bahamas, held. But Janet commented she didn’t think we were in the same spot. The GPS track showed our (power set) anchor on 175 feet of chain in 8 feet of water over hard mud had dragged 245 feet before stopping. We reset the alarm and racked out in total darkness.
The following morning on retrieval, we discovered that the anchor held because it was jammed in the throat of a knock-off seaplane anchor attached to a derelict boat that had sunk near our favorite spot during our absence.
We bought the SPADE several days later when the power finally came back on in Annapolis.
Hi.
Great post, we all need to be reminded that modelling and testing are only ever an approximation or simplification of what will happen in the big, wild world. On another point the inuit have recently been found to have a specific genetic modification that allows them to tolerate their high fat diet with impunity- the rest of us may find it less healthy. The French appear to eat less than their anglo saxon cousins. (avoiding transfats is probably wise, though)Again , more research required and we’ll probably find that it’s a little more complicated than we first thought.
Hi Bryant,
I think you make a great point: these things are far more complicated than many people recognize, whether it be anchors or heart disease. The problems come because it’s just human nature to gravitate toward a simple answer.
Hi
Concur with your thoughts on spade.
Using S120 on Malo 39 for last 5 years in UK and Medditeraen .
Previous CQR and Bruce just don’t compare.
Any suggestions foR a lovely 25kg Stainless steel Bruce sitting at home in Garage (UK)
Fair winds
Alan
When one reviews all the published research literature and testing on the new generation anchors versus the more traditional styles, (epidemiology?)
and take all the data into perspective, then the summation of all the test data agrees with the real world experience. The new style -concave- anchors are much much better then the old styles.
So, practical experience agrees with the science and testing. Whoopee!
Regarding that stainless steel Bruce anchor you have at home, I suggest it would make a nice lawn ornament.
In a few years it will be as outdated as those huge cast iron fisherman and Navy anchors that institutions and municipal governments love to use for ornaments.
Put that SS Bruce on the lawn I say, and get out in front of the curve!
I find anchor tests useful in the same way courtroom art is useful. They capture a moment in time, but they aren’t really evidence. That said, they do represent a start point in that they tend to weed out the less-useful anchor designs and *can* (but sometimes do not) point at anchor styles of good utility that aren’t always top of mind. Five years ago, I might have bought a Delta. Now I am, due not only to this site, but to testing I’ve seen, leaning toward the Spade and I like what I’ve seen of the Sarca Excel as well, save that it’s very difficult to obtain in Canada, whereas the Spade is not.
The fact that I know very good sailors who still swear by their Bruces and CQRs suggests to me that even a currently sub-par anchor can still hold given good technique and a proper watch. In that spirit, I do wonder if more effective anchors merely allow worse technique to be survivable, much as airbags keep bad or careless drivers alive to drive again another day.