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Forum Index: .: Dock Talk:
Which boat is faster?
Team McLube

 

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Teaky
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Nov 3, 2005, 7:22 PM

Post #41 of 63 (81510 views)
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Re: [DickDastardly] Which boat is faster? [In reply to] Log-In to Post/Reply

I think the white boats are faster. They cool the water down and do not absorb the heat from the sun. Therefore the water is cooler and closer to freezing temperature. The more the water is like ice, the slicker and faster it is. Thus, a white hull and the black sails will be the fastest. I think you can only get that color combination in the Beneslow, but I could be wrong.

Now if all three of the boats are white with black sails, then the one with the red spinnaker will be the fastest. We all know red cars look the fastest (e.g. Ferrari), and the same applies to red spinnakers. That is also why I carry a red bag - it makes me look fast and therefore I am fast.


willsail4food
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Nov 3, 2005, 8:05 PM

Post #42 of 63 (81499 views)
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I think the white boats are faster. They cool the water down and do not absorb the heat from the sun. Therefore the water is cooler and closer to freezing temperature. The more the water is like ice, the slicker and faster it is. Thus, a white hull and the black sails will be the fastest. I think you can only get that color combination in the Beneslow, but I could be wrong.

Now if all three of the boats are white with black sails, then the one with the red spinnaker will be the fastest. We all know red cars look the fastest (e.g. Ferrari), and the same applies to red spinnakers. That is also why I carry a red bag - it makes me look fast and therefore I am fast.


I disagree. The black(or dark) hulled boats would be faster. The hull would heat up the air inside effectively making it like a hot-air balloon. This would cause it to be lighter, and therefore faster than the white boats with colder, denser air inside.

Of course if all of the boats have black(or dark) hulls it would clearly be the boat with the most red bags on board.

P.S. why don't you post a pic of your red bag??


DickDastardly
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Nov 3, 2005, 8:09 PM

Post #43 of 63 (81497 views)
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I think the white boats are faster. They cool the water down and do not absorb the heat from the sun. Therefore the water is cooler and closer to freezing temperature. The more the water is like ice, the slicker and faster it is. Thus, a white hull and the black sails will be the fastest. I think you can only get that color combination in the Beneslow, but I could be wrong.

Now if all three of the boats are white with black sails, then the one with the red spinnaker will be the fastest. We all know red cars look the fastest (e.g. Ferrari), and the same applies to red spinnakers. That is also why I carry a red bag - it makes me look fast and therefore I am fast.


I think you are just jerking my chain, but if you are truly serious, let me explain in more detailed, yet in common, everyday language and terms that anyone can understand.

If we analize your suggestion, it would become readily obvious that if one has a black hull - just like the black sails, the hull and deck will absorb heat. I know (professionally) of few materials that contract when heated. Even simply high school physics would show that materials expand when heated - some more than others. Thus, if a hull/deck takes on absorbed heat by the very laws of nature, it MUST expand. I think if you give this extra thought you will concur.

Now - if you do agree that most forms of plastic (reinforced glass, fiberglass or carbon) will expand when heated by their modulus of elasticity following numerous and common physics lab examples, then I would submit the following...... it is really a black hulled boat that will be faster.

If you disagree, then think for a moment about how most all of our handicap rating systems work. If a boat is measured at a specific weight, along with other parameters of course, it is assigned a specific handicap number. Reading of any sailing forums will demonstrate that the weight of the boat (displacement) plays a critical part in the assigned handicap rating - too many have been caught changing weight (displacement) after the numbers are assigned - causing much anguish and grief for many race committees.

OK - so, if by logic you agree that a boats handicap rating is influenced by it's displacement, and if you agree a boat hull/deck will expand when heated, I suggest that the heating of a black hull compared to a white hull will cause the black hull to expand a greater percentage than an identical boat with a white hull. This proven basic rule of physics would then proceed to prove out the theory that if a boat "grows" (expands) when heated, the waterline length will change and become larger. This larger waterline length will change the amount of draft of a dark hull colored boat. Draft and waterline play an integral part on the boats actual displacement, which will also change as the hull "grows" bigger. Now if the hull "grows" bigger it will sit higher in the water and have less displacement. Less displacement of two identical boat hulls would suggest the one with lesser displacment might be faster. (and perhaps weigh less - but that is a different discussion). So in the end, the growth experienced by a dark colored hull contributes to it's actual enlargment, which in turn acts upon the assigned values of the handicap number assigned.

The concept of this "growth" is a naturally occurring phenomenom that is supported by many rules of physics. I have heard (rumor perhaps) of a boat in Chicago protesting an identical boat but with a dark hull, for being of different displacment than it was when the handicap certificate was assigned. The boat was painted after measurement a dark navy blue. This color contributed to it's suggested change in performance. Prior to posting this response, I checked a few protest postings for Chicago area yacht clubs, but was unable to come up with a direct quote. Along with trying to post this technical information that a layman could understand, I am having doubts as to whether or not you are trying to contribute to the knowledge of sailing - or if you are simply trying to offer a bit of humor. Currently it is difficult to tell.

Also your lack of knowledge is apparent by your suggestion that only a "Beneslow" (sic) is the only boat to have that color combination. Anyone involved in sailing would easily recognize that in the late 1970's Hobie Cat offered a 16 foot race boat called and marketed as the "WHITE KNIGHT" model. It came with white hulls and black main and jib. This combination was the forerunner of todays efforts and experiments in the evaluation and testing of black sail materials. The boat was marketed as a "race" boat and many proved to be very fast. Because the boat/class was a strict one-design, the use of black hulls to compliment the sails were not provided by the factory as they knew and realized that the hulls would "grow" in proportion to white colored hulls and wisely didn't enter the market. I am sure the fall-out due to protests within the Hobie 16 Class would have been a great embarrasment to both Hobie Alter and his sons. Imagine buying a white hulled Hobie 16 only to find out the guy next to you with black huls would have a longer waterline (therefore faster) catamaran than yours. This would have been disaster for Hobie Cat and they were wise in their decision to refrain from marketing black hulled catamarans. Soon after, the Tequila Sunrise sails were introduced, based on similar testing but while they were bright and eye-catching, they never performed as well as the old BLACK KNIGHT model.

While I am guessing that red Ferrari's have had their share of wins, dark blue Ford Cobras routinely put it to the Ferraris for several years until Ford exited racing. Truth be told, the change in size of race cars due to dark colors does not have the same positive effect upon their weight or displacement like it does with a high speed yacht. Also keep in mind that Dale Earnhardt was practically unbeatable driving his black Chevy, and of course we have aviation uses of black in the various new fighter aircraft. If you stop and think (if you are really serious) even red is a darker color than white - so in boats it could be quite possible that red is better than white (but still no where near as good as black).

Please rethink your response as I am sure you will see your errors.


DickDastardly
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Nov 3, 2005, 8:25 PM

Post #44 of 63 (81490 views)
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Re: [willsail4food] Which boat is faster? [In reply to] Log-In to Post/Reply


In Reply To

In Reply To
I think the white boats are faster. They cool the water down and do not absorb the heat from the sun. Therefore the water is cooler and closer to freezing temperature. The more the water is like ice, the slicker and faster it is. Thus, a white hull and the black sails will be the fastest. I think you can only get that color combination in the Beneslow, but I could be wrong.

Now if all three of the boats are white with black sails, then the one with the red spinnaker will be the fastest. We all know red cars look the fastest (e.g. Ferrari), and the same applies to red spinnakers. That is also why I carry a red bag - it makes me look fast and therefore I am fast.


I disagree. The black(or dark) hulled boats would be faster. The hull would heat up the air inside effectively making it like a hot-air balloon. This would cause it to be lighter, and therefore faster than the white boats with colder, denser air inside.

Willworkforfood...... While you have the right idea, the concept as you describe it simply won't work. Please consider the basic laws of physics in a similar manner as my post to Teaky. While you are correct about warm air being lighter (any good ballon enthusiasts will confirm) you must also consider (which you didn't do perhaps to lack of knowledge - no slam intended) that a sailboat hull has a variety of openings in the hull and deck. Even with companionway boards in place, there is still too much leakage of air from the hull. Your theory would work only if the hull was completely airtight. Through hull fittings, through cabin masts to be keel stepped, obviously the foredeck hatch opened for spinnaker raise and douse, even pope rivets not completely siliconed closed all would contribute to the leak. Also, much as a radiator hose in a car, the hull would soon become pressurized and could easily blow out all attempts to seal off such pop rivers, screw holes, etc. In fact, if left unattended, the pressure could build to the point of actually popping seams around windows, hatches etc. This might have been the cause of hull failure in several of the past America's Cup dark boat efforts. (that is a joke - please don't take that comment seriously) Seriously again, I am happy to be able to help you fellows understand the concepts behind these theories and I invite subsequent questions. After all, just think of the knowledge and education being passed on to other readers of this forum who are less inclined to discuss and debate. That is what is great about forums such as these - the sharing of knowledge and ideas amongst all the readers.


lat21
**

Nov 3, 2005, 9:36 PM

Post #45 of 63 (81481 views)
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Re: [DickDastardly] Which boat is faster? [In reply to] Log-In to Post/Reply

Wow! You must win the award for the largest pile of crap yet to be posted on this forum. I'm not talking stinkiest pile of crap, because I think you are far short of that one, I am simply talking word count of crap. That must have taken a good long while to write. Maybe you should consider going sailing or getting a girlfriend or something.


Steve Gregory
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Nov 3, 2005, 9:52 PM

Post #46 of 63 (81477 views)
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Re: [lat21] Which boat is faster? [In reply to] Log-In to Post/Reply

I think this place needs a Neighborhood Watch to maintain the peace.


J109Guy
**


Nov 4, 2005, 4:38 AM

Post #47 of 63 (81456 views)
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I would go for the j109 but it would depend on the wind strength, in the very light the j105 would come close.
you would win in the beneteau under IRC if you had a French certificate!

Wink


As the owner of a J109 that regularily races against 105s and 36.7s, I can tell you for a fact that in very light air the 109 has a decided advantage over the 105. With a much taller rig and higher spinnaker hoist than the 105 we just sail away from them in the light stuff. In VERY heavy air I would say the 105 has an advantage downwind as it is much earier to get them up on plane and surfing. The fastest I have been able to go downwind is 14.5 knots and it is hard to keep the boat surfing for long.

Versus the Beneslow, my experience is that we point a few degrees higher than them upwind and that they can sail deeper than us downwind. We race against a 36.7 called Sojourn and we are always within a minute or so of each other on the race course, it usually comes down to the PHRF math in the end. Of course that other 36.7 No Time IV beats us every time, but I think the two guys sailing her (Robbie Doyle and Jud Smith) have more to do with that than any boat to boat advantage.


Butt Monkey
Deleted

Nov 4, 2005, 6:12 AM

Post #48 of 63 (81442 views)
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OK - so, if by logic you agree that a boats handicap rating is influenced by it's displacement, and if you agree a boat hull/deck will expand when heated, I suggest that the heating of a black hull compared to a white hull will cause the black hull to expand a greater percentage than an identical boat with a white hull. This proven basic rule of physics would then proceed to prove out the theory that if a boat "grows" (expands) when heated, the waterline length will change and become larger. This larger waterline length will change the amount of draft of a dark hull colored boat. Draft and waterline play an integral part on the boats actual displacement, which will also change as the hull "grows" bigger. Now if the hull "grows" bigger it will sit higher in the water and have less displacement. Less displacement of two identical boat hulls would suggest the one with lesser displacment might be faster. (and perhaps weigh less - but that is a different discussion). So in the end, the growth experienced by a dark colored hull contributes to it's actual enlargment, which in turn acts upon the assigned values of the handicap number assigned. ------------------------------------------------------------------------ Dick Dastardly, It's not bigger, it's just the color, I swear. Don't be intimidated. B.M.





DickDastardly
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Nov 4, 2005, 7:51 AM

Post #49 of 63 (81580 views)
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Wow! You must win the award for the largest pile of crap yet to be posted on this forum. I'm not talking stinkiest pile of crap, because I think you are far short of that one, I am simply talking word count of crap. That must have taken a good long while to write. Maybe you should consider going sailing or getting a girlfriend or something.



lat21


please do not criticize what you cannot comprehend or understand. Simply enroll in any junior college of your own choice and sign up for Physics 305 and most of this will become very clear in due time. Because you don't believe or understand, is no reason to be so offensive.


Much of this information was previosuly discussed and detailed in correspondence with some well know designers of boats and technology. While I am not at liberty to devulge his identity, one former student as Westlawn (the boat design educational facility), and premiere builder of foil supported trimarans would probably concur with these findings. Unfortunately, he currently is deeply involved in canting ballast issues., and probably wouldn't find time to post here to confirm these concepts. This is not to say these are not legitimate theories. I would invite you to post any supporting criteria of your feelings, rather than taking on such a poor attitude.


lat21
**

Nov 4, 2005, 8:54 AM

Post #50 of 63 (81554 views)
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Re: [DickDastardly] Which boat is faster? [In reply to] Log-In to Post/Reply

That was no personal attack I did not say you were the biggest pile of crap, I said your post was. Take this for example:

"This larger waterline length will change the amount of draft of a dark hull colored boat. Draft and waterline play an integral part on the boats actual displacement, which will also change as the hull "grows" bigger. Now if the hull "grows" bigger it will sit higher in the water and have less displacement. Less displacement of two identical boat hulls would suggest the one with lesser displacment might be faster. (and perhaps weigh less - but that is a different discussion). So in the end, the growth experienced by a dark colored hull contributes to it's actual enlargment, which in turn acts upon the assigned values of the handicap number assigned. "

Ignoring the fact that the change in volume is infinitesimal, it is real. But sadly, it is a physics fact that changing volume will not change displacement. The boat will displace the same based on its mass. It might float slightly higher due to increased volume but it will displace just as much water. Floating higher reduces draft. Since the keel will be lifted ever so slightly this will reduce righting moment and... well enuf said.

I'm off to sail the Seattle Grand Prix. No more time today for this nonsense.


Danger
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Nov 4, 2005, 11:08 AM

Post #51 of 63 (81552 views)
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Wow- you guys amaze me. Did no one read my post concerning ball bearings. The only person who made any sense was Teaky (love the bag). Anyone worth their salt understands color only matters if you are sailing on wednesdays..in the rain. Otherwise the tropical flow pattern of the hyperbaric syncope is unrelated. High school physics anyone???!!!! The larger concern, it could be argued, is whether the fourth mode is available, or whether Mr Clean and Lesbian Robot are sailing. Also, if BG is taking one from his buddy on a jetski nearby, BJ may have to run him down in his Bene, since he will never be able to sell it to fund his FT 10 and blokart dreams.

nough said on this...I declare this thread dead!!!

baby arm!!


D4DR
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Nov 4, 2005, 11:35 AM

Post #52 of 63 (81544 views)
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And the colour of the numbers - after all we all know that air flows across a zebras back because of the mix of black and white stripes.


You say that in jest, but perhaps you don't realize it is true!

Consider, -- the color white reflects heat, while the color black absobs heat. When heat from the sun is absorbed, heat waves are produced. Heat rises. Think sailplanes and termal currents. As heat rises it creats a faint breeze. Meanwhile the white color is refecting heat and doesn't produce any "thermals".

When the zebra's black color causes these differences in gradient surface temperatures with the white, it is entirely possible that it changes (or at least impacts) the airflow.

Now, transfer this concept to a sailboat sails. Black sails will ALWAYS be faster than white ones, because of this heating of sail material and the change in boundry layer temperatures. It is found that air moves across black boundry layers much faster than when the color is white and thus one can gain a margin of speed differential from dark colored (or black) sails. I believe I read where North Sails has done an extensive research on this matter and was one reason everyone has pursued black carbon sails. Heat absorption and resulting differential in boundry layer temperatures have possibly proven this theory. Just consider that the entire sailmaking industry has moved from white (Dacron) to gold (Kevlar) to grey/silver (Mylar) to black (Carbon) sails during the last few years. I think there has to be a technical reason for these color choice changes.


No, I said it because i know it's true.


papa
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Nov 4, 2005, 12:20 PM

Post #53 of 63 (81531 views)
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SaltwaterCowboy
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Nov 4, 2005, 12:31 PM

Post #54 of 63 (81525 views)
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All this physics stuff is making my head hurt. Lesbian Robot, I really want to help, but we need some more information.

1. Is the J105 in PHRF config, or 1 design config?

2. Does the Bene have the dodger up?

3. Is the J109 the puke yellow Dr. Laura hull from CA?

4. Is the J105 wheel or tiller?


Regardless of the answers, the J105 wins except in really light air. As long as there's enough wind for the 105 to get within striking distance, the bene and the 109 would surely give way, RRS be damned.


Bird Man
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Nov 5, 2005, 12:36 AM

Post #55 of 63 (81416 views)
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Re: [SaltwaterCowboy] Which boat is faster? [In reply to] Log-In to Post/Reply

ok, saltwater cowboy, you must be a 105 sailor because you have this idiotic belief that a 105 will beat a benaslow or a 109, in no condition, configuration or anything will a properly sailed 105, of which there are none, beat a 109 or beneslow, and a 109 will destroy the beneslow no matter what. im preatty sure the phrf rating tell it all

J105 phrf 105 (give or take a few seconds for your area)
beneslow phrf 78 (see above note)
J109 phrf 56!!!

there is your answer

and on a side note, you guys need to get a life, pratice will help you get better and win , not the color of your boat or the color of your sails


sails call
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Nov 5, 2005, 4:03 AM

Post #56 of 63 (81409 views)
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Re: [Bird Man] Which boat is faster? [In reply to] Log-In to Post/Reply

Birdman - I agree with everything you've said. However, you need to add a few more footnotes:

1) White Beneteau 36.7s are faster in salt water, whereas dark hulled Benes are faster in fresh water.

2) In the Northern Hemisphere, toilet water flows counter clockwise. Bene's prefer to gybe set as the wind always goes right because of aforementioned toilet bowel effect.

3) Beneteau 36.7s are faster when the knuckle is in the water. That's why there is always a party in the cockpit.


JP
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Nov 14, 2005, 5:18 PM

Post #57 of 63 (81332 views)
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Windspeed and current velocity, please.


JP
***

Nov 14, 2005, 5:24 PM

Post #58 of 63 (81331 views)
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Black decks.


JP
***

Nov 16, 2005, 7:14 PM

Post #59 of 63 (81281 views)
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Re: [texas tim] Which boat is faster? [In reply to] Log-In to Post/Reply

It was a plebian question. Think about it.


bella
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Jan 10, 2006, 10:50 PM

Post #60 of 63 (81216 views)
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Re: [Teaky] Which boat is faster? [In reply to] Log-In to Post/Reply

...almost two months later...and no pics of the bag...dang...

Whichever boat has the manbag on it will be fastest...


Alun James
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Jul 26, 2006, 2:32 AM

Post #61 of 63 (81032 views)
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Re: [D4DR] Which boat is faster? [In reply to] Log-In to Post/Reply

It sounds really geeky but he is right.

A few years ago I was into archery and often watched my arrows go up and down in the air as they went from areas of shadow to light.


1boatbum
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Jul 27, 2006, 3:58 PM

Post #62 of 63 (81004 views)
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George W Bush is a sick puppy!!!

Enough said!!


bjfg144
**

Jul 30, 2006, 1:06 AM

Post #63 of 63 (80976 views)
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Re: [mighetto] Which boat is faster? [In reply to] Log-In to Post/Reply

Is the Macgregor 26x a sailboat or a wannabe!


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