Anyone happen to catch the recent article in Cruising World "Classic Plastic" section regarding the best cruising boats on the water. The CD36 made the top 25...just barely. It sounded like a bunch of (#$%^*&$^* but I'm interested if anyone got anything worthwhile out of it?
yoslovd@aol.com
Fuzzy Logic
Moderator: Jim Walsh
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Paul Grecay
Re: Fuzzy Logic
I plugged in the numbers for my CD28 and got nonsense results...I followed the formulae as written...and I'm no stranger to algebra...so I don't know if I'm missing something or if the formulae are published incorrectly or using some format unknown to me...Anyone else have a problem with them?
rfurman@dmv.com
rfurman@dmv.com
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Jim Stull
Re: Fuzzy Logic
HiDuane Yoslov wrote: Anyone happen to catch the recent article in Cruising World "Classic Plastic" section regarding the best cruising boats on the water. The CD36 made the top 25...just barely. It sounded like a bunch of (#$%^*&$^* but I'm interested if anyone got anything worthwhile out of it?
I plugged the data from my CD25 into the spreadsheet. I got good agreement with the values that I had previously calculated last year when I was deciding what boat to buy.
The CD25 comes out excellent in all catagories except for Ted Brewer's "comfort factor" value. As one can probably expect, the small CD25's motion in turbulent seas will not be as easy as a "good" bigger boat.
At least according to my results and with that exception, the spreadsheet results place the CD25 right up there with the best of boats.
I am certainly no expert with EXCEL but what I did to get logical results was:
1.insert a blank line directly under the "bold" heading on the spreadsheet
2.then enter the proper values for the CD25 in the appropriate columns.
3.copy the row below the new row and paste into the new row.
(Hope I did't forget anything)
Jim
jtstull@icubed.com
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Matt Cawthorne
Re: limitations
I scanned the article without trying to run any of the calculations and would like to make a few observations.
Each of the calculations tries to match what someone else thinks is an ideal number. Your harmony with your boat is a personal thing which you can't put a number to.
If the capsize screening formula used is the one which I ran on the CD-36 about 5 years back (I think it is) then remember that is a only a general guideline. At the time I was trying to sort all of this stuff out using my own brand of fuzzy logic. The capsize screening formula for the Cape Dory 36 was not as favorable as the Tayana 37. I later saw numbers published for the two boats and the positive range of stability (what the capsize screening formula is meant to give guidance on) and the CD36 was (as I recall) around 129 degrees and the tayana was down around 113 or 115. In this case the quick formula would give the opposite conclusion to what the more detailed calculation would give.
The d/l formula uses the waterline length. Cape Dory's have overhang which tends to make them look heavy. Had the bow and stern been a little more plumb, the boat could be made to look lighter. The hull would be the same thickness and the boat would weigh the same and probably would not perform any better. I can't speak for all of the Cape Dory line, but the 36 is peculiarly fast for the d/l ratio and I have heard the same for the 33. Again, the d/l is a good general guideline, but I wouldn't go rushing out to buy another boat just because you had some ideal in mind about what that number should be.
All of those formulas don't account for things like how well the boat is constructed.
You have to admit that most of the boats on the list were good boats. The best boat for you is the one which meets your criteria. For me, I knew that the CD 36 was my boat partly because of all of the numbers, but also because of the sense of harmony that I felt about the boat when I first set foot on her.
Matt
mcawthor@bellatlantic.net
Each of the calculations tries to match what someone else thinks is an ideal number. Your harmony with your boat is a personal thing which you can't put a number to.
If the capsize screening formula used is the one which I ran on the CD-36 about 5 years back (I think it is) then remember that is a only a general guideline. At the time I was trying to sort all of this stuff out using my own brand of fuzzy logic. The capsize screening formula for the Cape Dory 36 was not as favorable as the Tayana 37. I later saw numbers published for the two boats and the positive range of stability (what the capsize screening formula is meant to give guidance on) and the CD36 was (as I recall) around 129 degrees and the tayana was down around 113 or 115. In this case the quick formula would give the opposite conclusion to what the more detailed calculation would give.
The d/l formula uses the waterline length. Cape Dory's have overhang which tends to make them look heavy. Had the bow and stern been a little more plumb, the boat could be made to look lighter. The hull would be the same thickness and the boat would weigh the same and probably would not perform any better. I can't speak for all of the Cape Dory line, but the 36 is peculiarly fast for the d/l ratio and I have heard the same for the 33. Again, the d/l is a good general guideline, but I wouldn't go rushing out to buy another boat just because you had some ideal in mind about what that number should be.
All of those formulas don't account for things like how well the boat is constructed.
You have to admit that most of the boats on the list were good boats. The best boat for you is the one which meets your criteria. For me, I knew that the CD 36 was my boat partly because of all of the numbers, but also because of the sense of harmony that I felt about the boat when I first set foot on her.
Matt
Paul Grecay wrote: I plugged in the numbers for my CD28 and got nonsense results...I followed the formulae as written...and I'm no stranger to algebra...so I don't know if I'm missing something or if the formulae are published incorrectly or using some format unknown to me...Anyone else have a problem with them?
mcawthor@bellatlantic.net
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Duane
Re: limitations
Matt-Matt Cawthorne wrote: I scanned the article without trying to run any of the calculations and would like to make a few observations.
Each of the calculations tries to match what someone else thinks is an ideal number. Your harmony with your boat is a personal thing which you can't put a number to.
If the capsize screening formula used is the one which I ran on the CD-36 about 5 years back (I think it is) then remember that is a only a general guideline. At the time I was trying to sort all of this stuff out using my own brand of fuzzy logic. The capsize screening formula for the Cape Dory 36 was not as favorable as the Tayana 37. I later saw numbers published for the two boats and the positive range of stability (what the capsize screening formula is meant to give guidance on) and the CD36 was (as I recall) around 129 degrees and the tayana was down around 113 or 115. In this case the quick formula would give the opposite conclusion to what the more detailed calculation would give.
The d/l formula uses the waterline length. Cape Dory's have overhang which tends to make them look heavy. Had the bow and stern been a little more plumb, the boat could be made to look lighter. The hull would be the same thickness and the boat would weigh the same and probably would not perform any better. I can't speak for all of the Cape Dory line, but the 36 is peculiarly fast for the d/l ratio and I have heard the same for the 33. Again, the d/l is a good general guideline, but I wouldn't go rushing out to buy another boat just because you had some ideal in mind about what that number should be.
All of those formulas don't account for things like how well the boat is constructed.
You have to admit that most of the boats on the list were good boats. The best boat for you is the one which meets your criteria. For me, I knew that the CD 36 was my boat partly because of all of the numbers, but also because of the sense of harmony that I felt about the boat when I first set foot on her.
Matt
Very well said and thanks all for the great feedback. Honestly, I never looked at a single formula before buying our CD330. As you say, the harmony was just there when we stepped on board. My wife and I sat on the settee, looked at each other and said "this is the boat". We were not new to the Alberg designs. We had just sold an Alberg 30 by Whitby.
The boat sails like a champ and whether my sense of security is real or imagined...I don't think there is a better boat out there. I took particular pleasure in literally sailing circles around an Island Packet 38. The confused look on the skippers face as his eyes scanned from his sails to mine...you could almost see him mouth the words "..but I paid a quarter of a million dollars for this boat, I have to be faster".
Happy Sailing
Duane
Duane
Matt Cawthorne wrote:Paul Grecay wrote: I plugged in the numbers for my CD28 and got nonsense results...I followed the formulae as written...and I'm no stranger to algebra...so I don't know if I'm missing something or if the formulae are published incorrectly or using some format unknown to me...Anyone else have a problem with them?
yoslovd@aol.com