proceeding based on I-20 specs with a lighter proposed boat weight of 380 -similar class to other existing Formulas.
<br>
<br>-We have lighter boats by 40 LBs -more sail area in the main by 14.5 sq ft than the Euro F-20 ,-it automatically requires large crew to hold this boat down in a breeze.
<br> F-18 leaves off at 330 LB s,-is this a target and logical place to pick up the 20 Class.
<br> 330 min , allow 30 dead weight to min. -
<br>-What are ideal chute sizes and weights to allow more area.
<br> check 18 specs , and Euro 20 rules.-
<br>
<br> Min boat weight =380 ,-{based on Barry,s 388 weighing his I-20}
<br>Any can add lighter blocks lines hardware and gear to GET the I-20 to this .
<br>
<br>-Max mainsail =208 sq ft -existing I-20 is 208-_
<br>- 14.5 more than existing iF.
<br> note ,other mfg. may eliminate the lower window area and increase upper main slightly ,--are these types of mods allowed or should there be an exact overlay pattern as the 18s propose .
<br>
<br>-jib 53 spin 270 sq ft -same as I-20 --{no graduated jib sizes as per iF --ONE JIB max. --like the 18s ,-or should we allow mods ,--to smaller self tacking type if desired.
<br>
<br>--Larger spin allowance increase for larger crews ---crews over 360 recieve anadded ??sq ft ,--crews over 390 LB recieve an added ?? sq ft.
<br>
<br>Longer spin pole alum or c f and c f snuffer allowed , measured from f crossbeam .-{opt for larger chutes --heavier crews }
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<br> let us know -
<br> thanks -<br><br>

proceeding based on I-20 specs with a lighter proposed boat weight of 380 -similar class to other existing Formulas.
<br>
<br>Hi Carl. I agree... the beam limiation must be 8 and 1/2 ( I looked at the other box rules)
<br>
<br>-We have lighter boats by 40 LBs -more sail area in the main by 14.5 sq ft than the Euro F-20 ,-it automatically requires large crew to hold this boat down in a breeze.
<br>F-18 leaves off at 330 LB s,-is this a target and logical place to pick up the 20 Class.
<br>330 min , allow 30 dead weight to min. -
<br>
<br>MS.
<br>I would make it 350 min with 30 dead weight to min. The texel rating is for 150 kg crew for both f18 and f20. . IE 330lbs.
<br>My argument ... More sail... more crew weight.
<br>
<br>-What are ideal chute sizes and weights to allow more area.
<br>check 18 specs , and Euro 20 rules.-
<br>
<br>The F18's use 2 square feet differences between their large and small sail area for weight compensation. I suggest we keep that. so... small sail = 24 sq meters = the current inter20 size so make the max chute 26 meters.
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<br>Min boat weight =380 ,-{based on Barry,s 388 weighing his I-20}
<br>Any can add lighter blocks lines hardware and gear to GET the I-20 to this .
<br>
<br>Sounds good.. I believe John P noted that he could build boats at this range as well. One issue that the builders don't want to address is max boat weight.... They don't seem to publish any means + variances. Should the f20 class try to address this in any way. The f18's... have chosen to trust the builder that the boats will be similar. They don't want to weigh boats. What should the f20 class do?
<br>
<br>
<br>-Max mainsail =208 sq ft -existing I-20 is 208-_
<br>- 14.5 more than existing iF.
<br>note ,other mfg. may eliminate the lower window area and increase upper main slightly ,--are these types of mods allowed or should there be an exact overlay pattern as the 18s propose .
<br>
<br>I read the F16 rules. They use the term rated sail area which is from the Texel/ISAF rules. This seem to be the correct way to rate sail area.
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<br>-jib 53 spin 270 sq ft -same as I-20 --{no graduated jib sizes as per iF --ONE JIB max. --like the 18s ,-or should we allow mods ,--to smaller self tacking type if desired.
<br>
<br>I know the F16's debated this... seems to me that flexibiltiy should be encouraged. adding a self tacking jib is a plus. We probably need an expert opinion on how to write this one down.
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<br>--Larger spin allowance increase for larger crews ---crews over 360 recieve anadded ??sq ft ,--crews over 390 LB recieve an added ?? sq ft.
<br>
<br>I would consult a sail maker here as well. I think this is an important feature to keep in a formula class. if min is 350... i would increase the spin at weight of 380.
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<br>Longer spin pole alum or c f and c f snuffer allowed , measured from f crossbeam .-{opt for larger chutes --heavier crews }
<br>
<br>I hope that people will weigh in on this promising proposal.
<br>Take Care
<br>Mark<br><br>

I can certainly see us cutting a smaller jib in order to compete in F20. In fact we were working on something like this already,, for purposes of cleaning up the tramp area, by virtue of sheeting off the front beam.
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<br>What I am not sure of is how we might deal with the weight requirements. We currently weigh in at 295 on a heavy day, and ballast accordingly to our 305 class min.
<br>
<br>Personally, I would not want to see the min. class wieghts for F20 set so high, as has been proposed. If that were the case,, then some prospective F20 teams will be forced to move to F18, and/or stay in open fleet, which may remain strong on the local level anyway.<br><br>Keep at least one hull in the air !!!
<br>Alan Maguire

Alan said:
<br>If that were the case,, then some prospective F20 teams will be forced to move to F18, and/or stay in open fleet.
<br>
<br>I think this is a positive because we need to encourage smaller teams to go to the F18 so that we have two strong Formula Classes for different size people. The one thing that turns many folks off from racing cats is that they realize that thier size/weight is holding them back. When you look around at the winning teams and they are always right about minimum you realize that you brought a knife to a gun fight .
<br>
<br>I don't know if we want to mess with the 2 different chute sizes. The reason being that one size will be perceived as an advantage and everyone will try to run with that size anyway. At a 350 min weight aren't we already high enough. I know I would always try to run with more sail area given the oppurtunity.
<br>
<br>Mike Hill
<br>H20 #791
<br>
<br>Mike Hill
<br>H20 #791
<br><br><br>

Carl Said:
<br>
<br>proceeding based on I-20 specs with a lighter proposed boat weight of 380 -similar class to other existing Formulas.
<br>
<br>-We have lighter boats by 40 LBs -more sail area in the main by 14.5 sq ft than the Euro F-20 ,-it automatically requires large crew to hold this boat down in a breeze.
<br>F-18 leaves off at 330 LB s,-is this a target and logical place to pick up the 20 Class.
<br>330 min , allow 30 dead weight to min. -
<br>-What are ideal chute sizes and weights to allow more area.
<br>check 18 specs , and Euro 20 rules.-
<br>
<br>Min boat weight =380 ,-{based on Barry,s 388 weighing his I-20}
<br>
<br>MH: I would like to see more boats wieghed and probably set the weight a little higher is my guess but I don't know until we see a few more boats weighed. My guess would be 390lbs.
<br>
<br>-Max mainsail =208 sq ft -existing I-20 is 208-_
<br>- 14.5 more than existing iF.
<br>note ,other mfg. may eliminate the lower window area and increase upper main slightly ,--are these types of mods allowed or should there be an exact overlay pattern as the 18s propose .
<br>
<br>MH: The max at 208 sounds good. I don't know about the overlay. I think we need to give some basic parameters but allow the sailmakers some freedom also.
<br>
<br>-jib 53 spin 270 sq ft -same as I-20 --{no graduated jib sizes as per iF --ONE JIB max. --like the 18s ,-or should we allow mods ,--to smaller self tacking type if desired.
<br>
<br>MH: Is there a way to make the current jib self tacking? My guess is yes since it is currently run off the front beam. A self tacking jib should be almost a requirement on this boat.
<br>
<br>--Larger spin allowance increase for larger crews ---crews over 360 recieve anadded ??sq ft ,--crews over 390 LB recieve an added ?? sq ft.
<br>
<br>MH: I don't beleive this would be a productive rule. The percent difference at these larger weights is much smaller. I don't beleive that we will see anything but the largest sail area run on this boat so I think we should keep it simple with one size fits all.
<br>
<br>Longer spin pole alum or c f and c f snuffer allowed , measured from f crossbeam .-{opt for larger chutes --heavier crews }
<br>
<br>MH: Again not nessessary. But the snuffer would of course be allowed.
<br>
<br>Mike Hill
<br>H20 #791
<br><br><br>

Sorry to have been away for so long. I am happy to see that we are on basically the same wavelength.
<br>
<br>I happen to agree with Mike that the boat weight should be higher. I propose a compromise at 385. THe class can go back over weight minimums in a couple of years. I do think that the rules should state that the weight change can not go down more than 2% every three years. So basically, it gives us a few years to stabile the class, see what works, see what technology is there and inexpensive, before the weight goes down. (example: 385 minimum in years 2002, 2003, 2004 -- if vote passes the new minimum would be 377.35 lbs for years 2005, 2006, 2007) I don't think anyone would complain that their three year old boat is now obsolete due to 8 lbs. This would allow a boat to compete thru its livespan while enabling new technology to come into the class.
<br>
<br>On crew weight. I agree that 350 is the right line. It helps build the F18 class but also, brings alot of heavier f18 crews to NAF20.
<br>
<br>I also think that the sails should be set within parameters. However I really do like the maximum sail area concept. Where you are legal as long as you do not go over XXX sq ft. I would like to see some flexibility in this area but feel that the main and spins should be set to a max sq footage. Or do we want to allow a rule that states if you for go a jib than you can carry a % of the jibs area in the main and spin/gen configuration? Say additonal 30% of jibs sa in main and spin. I think this would do alot to take some of the pressure off the crews if we allowed this. Then the crew can run the main upwind and the spin downwind.. Most of us just set the jib and forget it most of the time anyway.
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<br>As for snuffer I think it should be mandatory unless the boat carries a furling reacher. This takes away the windage arguement. Also, holds the spin to a practicle size due to the limitations of the snuffer design. IE no worrell size spins because you can not snuff them.
<br>
<br>My two cents worth
<br>
<br>Steve<br><br>

Steve,
<br>
<br>I think mainsail sq ft has to be defined. If you just set a max total people will try to pile all of the sq ft into the main. This would lead to sail packages that would change quickly and making sails obsolete too quickly. It's a well known fact that you get the most out of your sail on the main because you use it on all points of sail.
<br>
<br>I think we should set a max sq ft for each sail: main, jib, and chute.
<br>
<br>Back to the snuffer. I think we should leave this open to crew preferance. Or we could require a snuffing type system. There is a lot going on in this area right now with the snuffer loop in the middle of the pole or even by the mast base. There is also the snail made in EU. So I would really like to see it left to personal preference.
<br>
<br>Mike Hill
<br>H20 #791
<br><br><br>

good posts ,-
<br>
<br>-On min.crew weight , several have suggested 350 ,-and a few have stated that they would be excluded from the 20 class at this 350 min. requirement weighing in at around 300 themselves , Alan Marc and others.
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<br> I am 6,4 -225LB - and have felt at a disadvantage sailing smaller cats unless it was blowing 15 to 20 , many larger sailors feel this way ,
<br>--actually gained 20 LBs one year to be able to add 50 LB of dead weights in place of a crew racing H-18s which was allowed within H-class rules.--a-fun year of racing ,but no one to talk stategy with or spot marks or countdown the start and spot the rival teams boats on the course, -
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<br>- -We should encourage as many as possible into the 20 class , If a 350 min crew weight is desired, then lets allow 50 in dead weights ,and allow weigh in wearing ,harness ,life jacket , and dry suit. -approx 8 to 10 LB s
<br> Equal weight is the goal ,-not to exclude 20 racing sailors .
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<br> This 350 min. would eliminate the need for spin size variables as Mike noted.
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<br>-Sail areas -main , -The reason 18s are standardizing is to simplify measurement , and allow mfg. control .,this also creates more of a one design type class.
<br> I don.t believe we can expect all new 20 designs to match the Inter , this would establish a very limited set of total design variables that would have to corespond ,plus eliminating all other existing 20 cat and 20 F designs .
<br> If we allow variation , we have to define the extent of that variation ,--The ISAF or Texel provides a means or standard way of measurement ,but not a class definition or exact sail configuration within a size limitation. -
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<br>-As we see in the A-Class developement of main sail area , numerous variations in sail outline of where and how this 150 sq ft of sail area is configured.
<br>-Effects =remember reading about an Aclass worlds racing championship where particular Italian A cats who typically raced in light wind conditions and had optimized their sail to light air ,-moving sail area up higher proportionally , -a larger sq top and added roach area, won and placed well the first day of the championships in light winds .
<br> The second day came in with much higher winds in the 12 to 15 range and the expected favorites won, while the light air designs dropped to the middle of the pack from then on .
<br>
<br>-Even within the same sail area there can be variations and performance differences , this is difference in allowing some types of limited developement as opposed to one design racing , and what we are attempting to define as a 20 class now.
<br> Again the 18s in N A eliminated this , partially for this reason , but we have different existing conditions.
<br>
<br>-One scenario a potential F-20 designer may go through .
<br>They may target a windspeed and design a 20 to that av windspeed, Barry noted his average in all regattas was 8 mph ,-light-
<br> The designer would optimize hulls with a low P C . shape and sections , typically dividing the hull in 10 equal areas along its length and drawing sections for each station.-
<br> P C is prismatic coeffient which is a measurement in section of the most volume as a total constant solid , in comparison with the actual hull volume .
<br> A low p c number has lower wetted surface , optimal to reduce frictional drag and better light air performance , A lower P C number is achieved by a hull shape with finer ends -{bow and stern } and more rocker -{more curve in for and aft lines of hull } .
<br> This design consistant with proper volume calc , for total crew and boat weights ,may also seek to minimize board and rudder areas .
<br> These features combined with all the other eliments of proper design and the aforementioned higher area sailplan optimized for light air would have much better performance in those ideal wind conditions.
<br>
<br>-Posted this so all understand more clearly the developement aspects even of this more limited type of class structure.
<br>
<br> To me it was not a large jump to propose more of a developement type class in weight to sail area trade offs ,
<br> with the proposed goal of including all existing 20 ft designs as they were listed and included previously , realizing refinment was required, but stating the existing conditions of current designs , which again we wished to include as a class rules goal and starting point.
<br> my appologies to those I was rude to in not explaining this goal more clearly , Realizing most do not have a basic understanding of cat design , though I am an amature .
<br>
<br> -If we can finalize these basics believe we can proceed with e mail in minor detail of rules , then set up a similar web site and get better contact with the other Formula groups to coordinate more events .
<br>
<br> Carl
<br>
<br>-<br><br>

Just some added clarification to the F-20 design scenario post above, -
<br>-All Formula classes are development classes to some extent, -the design variation between mfg., boat Cos. and builders effect boats differently in different wind and sea conditions.
<br>- The extent of development allowed in the F-20 class is what we are now defining. -With the goal of equal fair sailing for all and not some hidden advantage that suits our particular needs. -FAIR racing for ALL boats and crews, INCLUDING AS MANY AS POSSIBLE TO BUILD THIS NEW 20 CLASS.
<br> Again all formula classes are development classes to some extent; -hope the post above illustrates this.
<br> Barry, s 8 mph design with low P C and higher C E {center of Effort, sailplan would be noticeably faster in the light wind conditions it was targeted and designed for than the existing Inter 20. -The I-20 would become faster than the {Barry 8} as the wind increased, --sailing skill AND boat design along with development is part of the Formula racing game.
<br>
<br>-We are now agreed on the direction of proposing a 20 class largely based on Inter 20 specifications.
<br> -The effect of this and problem that I see is that we are now excluding and discouraging existing Formula 20 s from competing equally {class goal } as they have been built for iF rules and specifications of 418 LB min boat weight.
<br> Further effected are all existing designs we stated we wished to include in the new 20 class beyond the Fox and other iF 20S that we listed with specifications on this forum, The. -Nacra 6/0 –H-20s –Prindle 19s ,- Mystere , and several other potential racing 20 s, unless they can somehow get their boat weight from av 410 to420 to the 390—380 LB boat weight range and add a sailplan that matches the Inter specs..
<br>
<br>-The only viable solution and way we can include existing if20s at 418 Lb. and all other 20 ft catamarans listed now is to allow them added jib and spin sail area as a development design trade off for their existing additional boat weight.
<br>
<br>-Other Formula classes use trade offs of spin and jib areas for added crew weight, -we have proposed a higher crew weight to eliminate this, -but we can apply this rule equally to heavier existing boats to allow all 20s to compete on an equal fair basis, --The ratio is approx. 1 sq. ft per LB of spin, in a 30 LB difference a standard 30 sq. ft of spin area added to existing and older heavier boats weighing 410 or more. –Jib area increase from standard 53 sq. ft to –60 sq. ft, -with trade offs in area allowed from Max main to equal jib areas for variation in design.
<br>
<br>-This one added weight to sail area classification within the proposed rules will allow all existing If 20 designs to race on an equal fair basis with the lighter Inters and others, and allow all existing boats we previously listed along with their specifications a way to race equally and fairly within the 20 class rules structure. –Again all Formula classes are developmental to some extent.
<br> The advantages of including all in this class are huge; it encourages a race what ya got attitude and provides a means and way for all mfg., boats to race together. -Importantly it allows anyone to purchase an existing 20 or 20 platform, set it up basically the way they think best for racing, and to get involved in a very exciting Formula Class without the large expense of a new Formula specific boat.
<br>
<br>-beyond this needed correction ,we see 18 HP boats and a class proposed with a boat weight of 286 lBs as opposed to the 390 of the existing F-18 ,
<br> The new 18 HP cat designs will be much faster and more fun to sail and are less expensive,
<br>-Allowing sail area to weight catagories in a broader scope allows all equal length -beam cat designs a way to race fairly together as one LARGE developement Formula Class.
<br>
<br>-Carl
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