I couldn't let your PS Advisor of May 15th on Deep vs. Shoal Keels go by without some rebuttal. While your advice to Mr. Souval was substantially correct, it also serves to continue to promote some stereotypes that do the sailing world little good. To paraphrase and grossly oversimplify what you said: "Deep keels are good, shoal keels are ineffective, and centerboards have significant negative side effects."
Yes, yes, and not really. In the late '60s, centerboard yachts were doing very well as both effective cruisers and competitive racers. Finisterre is an obvious example. Then two things happened to kill the keel-centerboard configuration. First, Charley Morgan invented the high-aspect centerboard that could be hidden under the cabin sole, and second, in the political give and take involved in the framing of the IOR rule, centerboards were given performance penalties that far outweighed their well-known advantages. The boards hidden under the cabin soles by many manufacturers had serious maintenance issues, which soon led to serious reliability issues. Then, since most boats are fashioned after race boats, and the IOR rule discouraged centerboards, manufacturers stopped making keel-centerboarders. And since they were no longer making them, salesmen soon convinced the buying public that they didn't want them. However:
Extensive testing by the University at Delft, Holland (who developed the winged keel) showed that a good configuration of keel-centerboard is just slightly less hydrodynamically effective than a good configuration deep keel. The few inches difference in the height of the center of gravity between a deep keel boat and a keel centerboarder result in a very small difference in stability between the two when they are both being sailed properly.
It is certainly true that when the mast is parallel to the water, a centerboarder is more likely to continue over than a deep keel boat. But that is a seriously pathological case for most of us.
Whether a boat pounds or not in a chop has to do both with the sections in the forward third of the boat, and the weights of the ends of the boats. My old Herreshoff double-ender would hobbyhorse herself to a standstill if the waves were about 30 feet apart. My fat, flat centerboarder has a very smooth motion offshore, and is most competitive upwind in a chop in 15 to 20 knots of breeze. Go figure.
The reason for the above diatribe is that there really is a boat out there that has it all. It is the Nightwind 35, designed by Bruce Kirby in 1980. It is a comfortable cruiser that has a PHRF rating (when raced seriously) of 114. It floats in less than 3 feet and tacks through 80 degrees or less. It was, in my opinion, poorly marketed and indifferently built, first by C.E Ryder, then by Ft. Myers Yacht and Ship. Only 13 of them were sold. I have hull 13. The centerboard has no penetrations through the hull, and is neither a maintenance problem nor a possible hazard. I have cruised the boat for months at a time, from Georgetown in the Exumas to the Chesapeake. The boat is very competitive, and just won her most recent ocean race. I would like to see some manufacturer take advantage of this technology. (A couple of simple modifications to a Tartan 3500 would yield almost a carbon copy of the Nightwind, for example.) The East Coast is running out of six-foot deep coves either to anchor in or to dock in. There is a real need for a boat to fill this niche.
-Warren H. Miller, Jr.
Palm City, FL
Orienting the Gas Bottle
I just read your review of the Magma "Original Size" (#A10-007) barbecue grill. ("Six-Model Barbeque Test," July 1.) In it you mentioned that the Magma was "the only grill that wouldn't stay lit during the burger test." I own the "Party Size" grill and had a similar experience with it last year.
Over the winter I called Magma and told them that my grill was going out unexpectedly, and asked them if there was a fix for this problem. They told me to orient the gas tank so that it was angled downwind. Apparently the tubular fitting that slips over the connection between the tank and the regulator will allow too much air to mix with the gas when the tank is pointed upwind.
I made this adjustment this year, and have not had any flame-outs thus far, even when cooking in 20+ knots of wind.
Block Tackle From Pewaukee
Since my brother Peter invented and patented the first thermoplastic ballbearing blocks 35 years ago, and our company has made several million blocks in hundreds of configurations and bearing systems, I felt compelled to comment on your recent "Block Efficiency" article in the June 2002 issue.
I like PS and it provides a valuable service, but I was disappointed in thearticle for three reasons, disregarding the conclusions. First, the criteriaof evaluating blocks was shallow. Second, there are some significant errors in the facts presented, and third, the test itself means very little since the test is subject to multiple errors that are compounded beyond any reasonable tolerance.
We just spent a million dollars developing a new line of blocks called Carbo Blocks. Prior to doing that, we spent a few years with a lot of knowledgeable sailors around the world establishing the criteria for the new blocks. Price and efficiency were on the list but not as high as smaller,lighter and stronger to match the new lines and loads of today's modernboats. If we had designed a block to match your criteria alone it wouldprobably have had hardened steel ball bearings lubricated with light oil. Efficient and cheap, but not what we want on our boats.
Another performance characteristic which is usually over looked is that it is not the pulling in that matters, it is the letting out. We learned that in iceboats with 12-part mainsheet systems. Without free-spinning low-inertia blocks you could die if you couldn't release your mainsheet instantly. That is why modern ball bearing blocks have wide races with light plastic ball bearings. The test should have incorporated a multi-purchase system and measured the force at which the load releases.
The test was done on only one block with the line bending between80 and 90 degrees around the sheave. This does not leave much room for error since the differences in friction measurement are very small, and not having a series of blocks in a system makes it imperative to have very accurate measurement procedures. The friction difference on multiple blocks would be much greater and easier to measure with crude equipment like spring scales.
Also, putting a spring scale on both ends of the system instead of a known fixed weight on one end just compounded the errors since they multiply. Block diameters varied between 38 mm to 50 mm. That is over a 25% difference and of course the 50 mm block showed greater efficiency, which is primarily due to line friction which you talked about. That difference alone makes the test suspect. You also stated that the angle of the pulled line varied as much as 10 degrees around the sheave being tested. The load factor on the block therefore varied between 141% at 90 degrees to 153% at 80 degrees. Ifthe line load was 200 pounds, that means the load differences on the sheaves could change by as much as 24 pounds or 12%. If you add up all of the possible errors, the test could be off by much more than the differences you show on your chart. With an error factor this large the test is prettymeaningless.
Other notes: Harken and Schaefer apparently have different definitions of "safe working load." I would like to make sure that readers do not think that Harken blocks start to fail when that load (according to our definition and specifications) is exceeded.
Harken blocks are not made in Italy. They are all made here in Pewaukee, Wisconsin. Our winch factory is in Italy. The universal three-way head is not a modern development. It is shown on the first Harken blocks in the 1968 Land's End Catalog.
This was indeed a non-rigorous seat-of-the pants experiment. We considered using a fixed weight, but decided instead to try a set-up that would roughly simulate a mainsheet system, with shock cord representing a sail-loaded boom in light to medium air, the four-part tackle as the sheet tackle, a block to redirect the sheet, and finally the block being tested. The test block was the only element that changed, and considerable care was taken to make sure the other elements were reset equitably between pulls. (We only had one copy of each test block in hand—a test with identical blocks in all parts of the system would have been better, certainly.) Even with the careful re-zeroing, we were aware that the system was mushy, and that there would be considerable error built in. This was why we made 15 pulls for each block, randomly in three pressure ranges, and randomly varied the angle of pull within a 10-degree range. (We tried to keep the speed of the pulls equal.) That way, at least we could get results that would be reasonably similar in their message, if not their precision, to results from a more rigorous test.
We considered the numerical results instructive, even if mushy, but didn't make a big deal of them in the article. We said that the differences we could detect at those light loads with our spring scales and eyeballs were so slight that, given only those criteria, we'd rely more on price.
We've received letters from several readers, including Dave Dunavan, Tony Smith, Brion Toss, and Jon Fitch, with constructive criticism (including talk of sines and cosines) of the test method, and intelligent commentary on blocks in general. Their letters are detailed, and rather than try to whittle them down, we'll put them whole into Mailport Online on the PS website.
Regarding your comments on "head hose sclerosis," there's another solution to the problem. Simply flush the system with fresh water for some hours, and this will disolve all the crystals.
I have a Lavac head (I see no reason to buy any other) and there is considerable tubing on the way to the through- hull, removing which would be a nightmare. I made a stopper with a garden hose going through it, to which I attach my water hose. I run a small water rate, say, overnight. The water pushes right through the pump valves and in the morning the system is clean.
I do this about once a year. Yes, it uses a bit of water. I am assured that the US Navy does the same thing, and that one medium-size vessel would use more water in a couple of weeks in dry dock than all the yachts in the country put together.
I installed the head six years ago. Have lived on it continuously during a circumnavigation and have never had to remove the tubing.
-Robert Ashton, S/V Chandelle
Plodding Luddites Unite
Astounding! The instruction book for every GPS chart plotter has a line something like, "Electronic charts are not a replacement for traditional charts." Every sailing magazine on the market has a mention of this in some context nearly every issue. Practical Sailor has published dozens of remarks regarding this matter in answers to questions or equipment evaluations. Somehow, people just do not get it.
From Mailport letters in the June issue: "...then carried all my paper charts back on board." Because the chips were expensive! Or , "I would call the paper charts a supplement to the electronic charts."
I have sailed for 47 years and flown for 43. In that time, everything that can fail on a boat, plane, or helicopter has, at least partly. Things electrical, and especially electronic, head the list. The failure is often something highly technical such as a corroded connector or discharged battery. I know my home waters and airspace well and have both GPS and Loran on both boat and airplane (and a few other goodies), but would never leave the hangar or dock without proper, current charts on board. Loran stations need maintenance; satellites get the wobblies; batteries crap out; shoals move; switches do not contact.
The electronic toys are great. I love them. But please see them as conveniences; very fragile conveniences. Act cool, but think Luddite.
I recently received your April 1 issue and would like to comment on "Choose Your Own Seductions." I fully concur but would like to elaborate on your comments about the use or lack of use of the common compass. We have been cruising for the last two years and are now in Panama. Recently our Ritchie compass lost its fluid and therefore became inoperable. Well, I would like those who believe they no longer need a compass because they have GPS to try to get along without one if it is a pitch dark night, heavy seas, the boat is getting thrown around, and there is no sky nor stars to steer by, and the autopilot is on the fritz. Try to do this with a GPS—close to impossible in my opinion. Yes, one can set up a delay in the GPS to eliminate the rapid back and forth course indication, but try to do this in a storm. I for one simply could not do without a compass and its dampened display that lets me keep a more or less straight course under those conditions.
-Thomas C. Knueppel
Smart Battery Fix
In the March issue, Steve Dashew described a problem with his Furuno Fax 207. Aboard Joyant we had a similar problem with our Fax 207 with a loss of all programmed data after two years. There was no place nearby to have it repaired since we were in Alaska, so we had it fixed in Seattle. The problem was a small soldered-in memory holdup battery that has, according to the manual, a two-year life. Two years later it went again.
I was annoyed at the expensive and inconvenient process of replacing this battery, which always fails midway between two distant dealers.
Furuno was no help in solving the problem but a dealer confirmed that any 3-volt battery would work to keep the memory up.
I went to Radio Shack and bought two 1.5-volt mercury AA batteries and a plastic case for them that had pigtail leads on it. I then unsoldered the old battery and soldered in the pigtails. There was plenty of space to screw down the new battery case inside the fax case. The soldered-in battery has the polarity marked on it and you have to be very careful to install the new battery with the same polarity. The two AA cells are probably 10 times the size of the Furuno battery, so should last a long time. When they do fail, replacement will be easy. So far they have lasted well for over two years.
-Tom Wadlow S/V Joyant
Regarding Scott Rosenthal's use of Spartite, I hope it goes well. Ihave had Spartite instead of mast shims for five years now. It workswell to support the mast at the deck, but it does not and never hasacted as a sealant to keep out mast leaks. If I didn't use very carefully applied mast boot tape, I would have a flood belowdecks with every rain storm. The problem appears to be that the mast moves despite the Spartite when the boat heels, and this creates space between the mast and the deck partners.
My system was applied professionally by an excellent yard. When I called Spartite about this (a week after the intial installation), theysuggested that I fill the space above the Spartite with silicon sealant. This had virtually no effect. They also pointed out that they do not guarantee watertight integrity. At one point, I was desperate enough to use roofing tar, which worked for one season but which was a gross mess to work with.
This year, I have tried a layer of blue gasket gunk (in a tube) followedby a marine sealant. Then I used three rolls of 100" mast boot tape sealed at the edges against the mast with sticky rigging tape (at $30 a roll).
One year I had good luck using shrink wrap around the mast base above the deck. Unfortunately, it wasn't too neat a way of doing things and the heat gun caused the paint on the mast to bubble. Heaven knows what will eventually really work.
Access to ABYC
Thank you for clarification on the relevant certifications and ratings that affect boatowners. I have a complaint with ABYC, however, and wonder if I am alone in this. I often read articles and books by experts who quote ABYC standards, and these standards seem to be well thought- out and set a reasonable goal for me to strive for as I maintain and improve my boat. These standards, and the organization that develops them, are industry-driven and financed by the purchase price of the products that are developed. I would think, however, that it would be appropriate for non-commercial users to have access to this information at less than industrial prices.
There are 68 standards, and the cost to buy them is $40-$80 each (see www.abycinc.org). The entire set can be purchased for $219, but only if one is a member of the ABYC, at a membership cost of $148/year. It would seem that we as boatowners/consumers ultimately pay for this anyway, and inexpensive access to the information for individuals could only help to make the sport safer for all.