We have numerous existing 20 ft cat designs in N A in the 410 to 420 range listed with their basic specs on the F-20 forum, we also have existing iF20s in the 418 wt range with most actually weighing just below, -We have the Inter 20 in the 385to 390 weight range, with a 15 sq. ft larger main than existing If20 designs like the Fox. We would also like to encourage and promote lighter H P 20 designs to evolve within the class rather than see them form as a separate HP class as we are now seeing occur in the 18F Class in separate F-18 and H P 18 Classes.
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<br>-It has been recommended to base the class largely on existing Inter 20 specifications –of main sail 208 –jib 53sq ft. spin 270 sq. ft. as a guideline with more tan 200 existing in the U S presently.
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<br> A sail area to total weight rule allowing trade off of weight to sail area is proposed in amounts to equalize performance ratings and under ISAF and Texel rating numbers. Other Formula classes presently use sail area to crew weight trade off but only applied to larger crew. With a class goal of including all 20s listed and new potential designs through a wide weight range a more comprehensive and inclusive total boat and crew weight to sail area formula is required to achieve fair sailing for all through this varied boat and crew weight range .
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<br>-3 categories are proposed with an additional added in 02 for lighter H P 20s. The first covering most existing active racing catamarans in N A and existing If20 designs like the Fox in the 410LB boat weight and above category with a targeted crew weight average of 330 for a 740 total in category 1
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<br>-Category #2 is all cats similar in weight and general specifications to the existing U S version Inter 20 using a base boat weight of 380, + av. crew weight of 330 to a total of 710 LB. –Per existing I-20 specs. Similar sail areas would establish the base for all weight classes, Category #2 –mainsail 208 sq. ft inc. mast –jib 53 –spin area 275 sq. ft.
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<br> Category #3 would drop an additional 30 LB. To a boat weight of 350LB-+av. Crew weight of 330LB to a total of 680 LB., New designs are presently being built in this category. Proposed sail area to weight formula per 30 LB increments in each category are 3 sq. ft jib –10 main –and 25 sq. ft in spin. Sail area.
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<br>-Category 3 ---MAIN = 198 SQ FT ---JIB =50 SQ FT ---SPIN =250 SQ FT --TOTAL WT 680 LB.
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<br>-Category 2 ---MAIN =208 SQ FT ---JIB 53 SQ FT ---SPIN 275 SQ FT ---TOTAL WT 710 LB
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<br>-Category 1 –MAIN 218 SQ FT --JIB 56 SQ FT --SPIN =300 SQ FT –TOTAL WT 740 LB.
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<br>-note; sail areas proposed to be revised per ISAF rating and designers recommendations .{pending final revision }
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<br>-SAIL AREA notes; -All designs may trade equal amounts of sail area from main to jib to allow sail plan design options and existing modification.
<br> -All teams will be allowed one additional sail of each type.for any race or regatta as a replacement,.
<br> -All sails to be labeled per size in 2 inch easily readable form at the tack next to the sail makers logo, all new sails to be listed and signed over the sq. ft 2 inch sq. ft. number per sail maker.
<br> Roller furling sails and reef points for the main are allowed, as is the spin snuffer.
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<br>-AVERAGE CREW WT. –av. crew weight is 330 LB –crew weight effects allowed sail area per category weight, a 360 LB crew moves up one category and is allowed proportionately more sail area as listed, a 390 crew moves up 2 categories in total allowed sail area. A 390 crew sailing a category 3 lighter boat but equal in total weight as the average 330 crew sailing a category 1 heavier boat but both having total equal weight would be allowed the same rated sail areas. This equalizes total weight to sail area, in other instances it equalizes rated performance. A 30LB heavier crew and boat receives 25 more sq. ft of spin area, -10 more sq. ft of mainsail area, and 3 of jib in any main to jib configuration of equal total sail area.
<br>-Two additional sail area categories will be added at the top for heavier crews sailing heaviest category boats only.
<br>-Category 3 boats will have a min. 330 crew wt until a category 4 is established .All crews may carry weights to maintain the category of their choice. Any boat may race with less than max. Allowed sail areas.
<br> EXAMPLE –applied
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<br> Currently we have the Fox in its existing weight of 418 to 410lb –Category 1
<br> It would be allowed an upgrade from its present 193 main inc. mast to a 218 sq. ft main area or 10 sq. ft more than the Inter 20; currently the Inter has 14.5 SQ FT more mainsail area than the existing Fox.
<br>The Fox would also be allowed a 25 sq. ft larger spin, If a 50 to 60 LB LIGHTER version of the Fox came out the opposite would be true, given similar crew weight to meet each respective category.
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<br>All formula classes are developmental to some extent, this requires racing sailors to modify and target their boat of choice to a particular category set up any way they choose with any combination of rudder boards, sails gear mast rigging or basic platform to class rules outline.
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<br> This proposed formula 20 class does potentially include every active 8.5 beam racing 20 footer within its scope. One large diverse active racing 20 class ideal for distance or buoys racing. One design can be maintained inside it as desired, some will not comprehend formula racing or the merits of it but believe it has the potential to bring in all existing dead boat classes, creates a wonderful opportunity for sailors to refinish and rebuild many existing excellent 20 designs at very reasonable costs . It insures the 200 plus existing Inter 20s will always be part of the racing 20 scene ,and allows new lighterweight exciting boats to be created ,and be able to participate in a large exciting fleet of avid catamaran racers.
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MFG comments and specifications =-Nacra 6/0
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<br>This twenty foot pure performance machine boasts:
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<br>The number one racing catamaran in the 20 foot range
<br>High-tech bow foil system
<br>Utilizes features of the successful Nacra 5.8na
<br>Over 250 square feet of sail area
<br>An 8'6" beam
<br>If you want the biggest, fastest, the ultimate, the NACRA 6.0na is just what you've been looking for.
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<br>All the speed of the 6.0na is made manageable through innovative control systems and quality Harken fittings throughout.
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<br>The fully battened mylar mainsail features a boomless sailplan with a unique clew traveler system providing a powerful yet controllable boat.
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<br>Length: 20' (6.10m)
<br>Width: 8'6" (2.59m)
<br>Drafts:
<br>Boards Up: 5" (12.7cm)
<br>Boards Down: 38" (96.5 cm)
<br>Sail Area: 264 sq. ft. (24.5m2)
<br> jib 67 -main 197
<br>Weight: 420 lbs. (191 kg)
<br>Mast Length: 31'7" (9.63m)
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<br>-The 6/0 in Formula racing would place in the Catagory 1 at 410 and above boat weight with av 330 LB crew to a 740 LB total .
<br> Existing 6/0 sail areas are within approx. 10 sq ft of max allowed in catagory , and would be allowed max. spin area in catagory or more sq ft as per crew weight .
<br> The platform , boards rudders mast gear equipement or sails may be replaced or modified as the owner chooses. The boat will be very competitive as is .
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<br> Note ; this cat has a heavier mast with added stays and may along with cats with existing heavier comtips , be the only existing cat designs to request {dispensation } in spin area.
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<br> Looking for active 6/0 sailors recommendations in this area and as to potential modification and general tuning improvements for this excellent racing cat .
<br> Hopefully eventually photos and an article on setting up and racing the 6/0 .-<br><br>

Builder
<br>Hobie Cat Co. (USA)
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<br>Designer
<br>Jack Groeneveld
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<br>Specifications
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<br>Length: 19 ft. 6 in. / 5.95 m
<br>Beam: 8 ft. 6 in. / 2.60 m
<br>Draft, board up: 0 ft. 5 in. / 0.13 m
<br>Draft, board down: 2 ft. 9 in. / 0.84 m
<br>Displacement: 420 lbs. / 190 kg
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<br>Builder's Remarks
<br>Meet the cat of choice for racers around the world. Specially engineered to set a rapid new pace for the 90s, the Hobie Miracle 20 is designed with every "go fast" feature imaginable, virtually all as standard equipment that would be costly options on other boats. The Harken 8:1 downhaul and prebent Comptip mast enable power at the top of the sail to be controlled, even while trapezing. And, with Harken equipment throughout, quality is guaranteed. For even more control, all jib sheet, jib lead, downhaul and mast rotation adjustments can be made from the trapeze.
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<br> --The Hobie 20 would place in catagory one 410LB boats and above with av 330 LB crew.It could upgrade sail areas allowed per catagory making it equal in performance rating with the Inter 20 . The Hobie 20 being allowed more sail area in proportion to added total weight.
<br> The existing Length of hulls would allow a v shape transom extention to a full 20 ft if desired . Basic platform ,boards, rudders,mast ,gear,equipement and sails may be modified per owners requirements and individual sailing style.<br><br>

The Prindle 19 is:
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<br>sloop rigged, symmetrical hulled design
<br>race equipped
<br>If you are looking for the ultimate combination of sailing performance and strong class racing, the Prindle 19 is the catamaran for you!
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<br>Length: 19'2.5" (5.85m)
<br>Width: 8'6" (2.59m)
<br>Drafts:
<br>Boards Up: 5" (12.5cm)
<br>Boards Down: 25" (63.5cm)
<br>Sail Area: 247 sq. ft. (22.95m2)
<br>Weight: 385 lbs. (174kg)
<br>Mast Length: 30'3" (9.22m)
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<br>----The P-19 -Is a catagory #2 boat at 390 LB with av 330 wt crew , and could match the Inter 20 sail areas per class max , or would be competitive raced as is . -
<br> Carbon masts are allowed on all designs , as well as snuffer systems for the spin , max pole length to be determined per recommendations. -<br><br>

Tornado --mod to 8.5 beam for Formula-
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<br>-Length-6,10m
<br>Beam 3,05m
<br>mast 9,20m
<br>weight-169kg
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<br>main17m2
<br>jib7m2
<br>spin25m2
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<br> Potential Formula 20 racers may wish to take an existing platform like the Tornado , which like so many older cats have been adandoned and can be purchased very inexpensively and modify it to Formula 20 .
<br> The Tornado hulls are lightweight and would be in catagory 3 with av crew weight or catagory 2 with more crew weight allowing equal sails areas to the existing Inter 20 .
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<br> This would be potentially very inexpensive as I,ve seen T-for sale for under 2 k and be very competitive on the race course beyond always being a classic enduring design. <br><br>

Inter 20 basic specs .
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<br> -Weight 285 to 290-
<br> sail ar main 208 inc mast -U S version
<br> sail ar jib 53
<br> spin area 270 -
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<br> The Formula class is based on the Inter 20 basic specs and existing sail areas , boats are the model for the class.
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<br>-Catagory 2 total weight is based on a 380 min boat weight with average 330 LB crew. 710 LB TOTAL -
<br> If your boat weighs 390 and have a 320 crew wt. it meets Formula rules , crews below this may carry weights , crews above 355 Lb may add additional sail area or not in accordance to total weight to sail area catagory.
<br>All teams are allowed 2 of each sail type approved .
<br>-Note on crew wt and total wt -
<br> A min.wt would only apply to the lightest boat catagory , all others are self correcting .
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<br>- I would like several cat designers and others opinion on accurate sail area to total weight allowances , beyond rating numbers it may require more specific individual boat performance prediction programs designers use having more specific targeted info on crew and boat wt in a 20 ft 8.5 beam design. -
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<br> Carl<br><br>

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<br> Existing Euro Formula 20s are some 30 LBs heavier and have 14.5 sq ft less sail area in the main . these are EXISTING CONDITIONS .
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<br> The Fox and other excellent designs are per example in the original post as presently built in catagory 1 and allowed proportionately more sail area per total boat and crew weight catagory.
<br> -All mfg, and boat builders could build lighter versions similarly for the U S market to match the Inter class spec basis model , or even build lighter with correct sail plan options in 2 catagories with added spin options , or even offer basic plarforms .
<br> The Storm , Ventilo , Fox , and others would certainly have better oportunity in the U S market by targeting a better boat than the existing class model Inter , also knowing their is a viable 20 class of active racing sailors to accept them for fleet regattas and distance races.
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<br> We would appreciate greatly input or recomendations any boat mfg. or builder would care to add , particularly in establishing final sail area to weight ratio numbers -
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<br> Happy Holidays
<br> Carl Roberts
<br> crdesignr@earthlink.net<br><br>

Carl,
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<br>Beautiful work ! It would be nice to have everybody agree with this.
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<br>I hope that I can get the sail area to ratio program based on the ISAF fomulas in the next couple of days. Hope this can give us an accurate guideline for sail area per weight.
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<br>I also like the idea of sailarea being transferable from one sail to another. This should make it a lot less expensive if all you need to do is to have 2 jibs for different weight ranges.
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<br>marc
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Hi Marc



Let us know how the program is going ,-



Thanks

Carl - crdesignr@earthlink.net