Looking for clarity because I've seen many different interpretations of whether the F18, F16, F14, and A-Cats are formula or box rule classes. Further, I suspect that the usage of "Formula" for the "F" series classes contributes to the confusion. Of course, I am leaving out the Nacra F-17 which is actually a one-design (?) .

My understanding is that a true "formula" class is exemplified by the 12-Meter keelboat class where it is a function of length, beam, displacement, and sail area (simplified). All of the variables must result in 12 meters via the class' formula. Accordingly, 12-meter yachts typically range from 20 to 23 meters in length because of the formula. Length is dictated by the formula, not by a maximum length constraint.

Whereas, a true "box rule" class defines limits, maximums (ie: length) and minimums (ie: weight), and all boats must measure within the constraints or "box". However, box rule classes do not preclude the usage of formulas. Sail measurements for all of the aforementioned beachcats employ formulas to calculate sail area; however, the resultant sail area is still subject to maximum constraints within the "box" rule.

SO....is it correct to say that F18, F16, F14, and A-Cats are technically box rule classes, not formula classes?

I suspect that the usage of "formula" for the formula series beachcats comes from the conceptualization of the Formula 18 class via SCHRS formulas to compute performance parameters (per International Formula 18 history website page)? The label "formula" stuck and was adopted with by the similarly subsequent F14 & F16 "box ruled" classes. "Formula" certainly is more sexy than "Box Rule 18 or BR18" from a marketing standpoint.

Plausible explanation? Is there more to it? I did not wish to muddy the waters with development vs semi-development nor "open class" topics. Thanks in advance for any further insights.

Hi Kris
I think you summed it up pretty well.
I would take issue with this statement.

I would change it to "SCHRS or Texel formulas to compute performance BASED on measured parameters."

I think the historians would note that the Formula part of the name was driven by the notion that the rules allowed you to use a crew weight formula and come up with a different sail plan to match your team's size.

The Nacra F17 class used the same argument to match two spinakers to sailors of different weights.

I don't think it was quite as marketing driven as you conclude. Now a days... the Formula part is indeed just marketing the brand... eg Kleenex... for tissue paper. The small sail plan appears to be not truly competitive with the large sails.

Mark-

I lifted that part from the International F18 website as my attempt to discover how "formula" became part of the name for box rule classes. It may be a case with translating to english relative to phraseology.
International Formula18 History .

Not true. The only people who say that have never tried the lower weight category and small sails. The formula works great; if anything, I think the small sail plan is favored. Same main sail, and the newer designs have tremendous buoyancy... makes a light team scream upwind and sail deeper/faster on the run. Personal experience both as a skipper and a crew on the Capricorn, Infusion and C2 with big and small sails, and on the Wildcat and Tiger in addition.

Kris,

What is the reason you are asking, other than morbid curiosity?

I think you did a great job of digging up enough info, and from what I know of the rules (minimal compared to many here), I would say that there are elements of both box rules and formulas for each of these classes.

Again, not really sure what the label buys you here.

Mike

Mike,

I do have an agenda and admit that I have only been racing "formula" class boats since 2007 so I have much to learn about the inception of the "formula" beachcat classes. I am an advocate for the "formula classes" concept and see many strengths that it has to offer relative to racing, sailors, and manufacturers. I see nothing but growth for these classes.

I frequently come across both catamaran and monohull sailors that immediately think that we are "true" formula classes and not box rule classes based on the name. As part of our advocacy, a colleague and I are meeting with a sailor who successfully campaigned 12-Meter keel boats in the America's Cup. Accordingly, I would like to be prepared when asked why is a "box rule" class labeling itself as a "formula" class. The 12-Meter's Formula Class existed long before the concept of F18 beachcats. It is easy to understand that the F14 and F16 classes adopted the same nomenclature established by the F18 class because they utilize similar class concepts and objectives. However, I am grasping for a definitive reason why the "box rule" Formula 18 class elected to use "formula" in its name.

Formula rules can limit building materials also .Box rules do not.
A and C class cats are box rules- You can use anything to build them.Sky is the limit.
The F-18s are formula because of material limitations( aluminum stick, No carbon, etc). I can't speak for F-16 because I never read their rules.

At least that's my take on it.

I would say the F18's and F16's are actually Box type rules, as there is no real "Formula" or math exercise involved, just a measuring of maximum and minimums; length, width, weight, sail area, etc.

So...should we now rename our classes; B18 and B16?

;^)

Todd... I think that your definition is simply your take on it.

The limitations that you think makes for a formula vs box rule are better described as class rules... similar to the no electronics rules that classes may choose.

The larger sailing community assumes formula class means a mathematical equation which is the design rule. Those rules give you boats with a certain look. The goal was to work within the formula and come up with the fastest design. See 12 meter AC cup rules.

Then you have classes that form around some sort of RATING Rule... The idea being that boats designed to the rating would be one design in performance but have slightly different choices for the owners.

I have never heard of an F18 Formula... much less seen the math.

My read of the F18 history was that they had a Box in mind... 18 feet and max beam of 8'6 inches and 400 or so pounds. They also wanted the largest crew weight optimum and so they wanted one platform with two sail plans for crew weights. They had strong opinions on what the class rules must be so that they could stay independent of the major builders and continue with development in a controlled manner to preserve an owners value over time. So... the A class and C Class are simple box rules... (remember the Tornado is a B class boat) The F18 is a more complex box rule with many restrictions. A one design class is the most restrictive box of all...and in the end... they simply don't allow anything they did not build... even if it were identical.

I am pretty sure the Formula simply refers to the crew weight Formula they use AND to brand the class as distinct from the Hobie Tiger, Nacra inter 18 and Dart Hawk one design classes they were sucking in and to distingish the class from classes run by the builders. Remember, these one design classes had one sail plan and minimum crew weights to go along with the manufacturer only equipment restrictions.

The F16 class debated the alternate sail plan idea as part of the basis of their Formula for their F16 Box. ... They nixed the idea because the EU opinion was that the two sail plans did not live up to the billing (sorry JW). Their formula was the pretext that that by dropping the jib and hardware they would equalize one up and two up racing... with first across the line wins... They justified this assertion by computing the texel rating formulae and noting the slight differences should be fair around the race course. Again... this is NOT a formula class... rather a box rule with restrictions... (of course some would argue... not enough restrictions but that dog has been quiet lately)

Kris, My solution... explain the classes called Formula as crew weight formulas added to a box rule with nothing to do with design rules. Most big boat sailors are not that familiar with box rule classes either and so the general confusion with formula rules, rating formula classes and box rule big boat classes is just too deep . The simple solution is understandable and handles the real issue. Will my boat choice be obsolete tomorrow and in 5 years. ...

I always thought of us, F18s, as being a box rule boat with lots of restrictions. Those include the materials that the boat is made of as well as all the weight and sail area limitations. We fit in a box that was established, but have further to go with all our restrictions, not imposed on the box rule boats, which makes all the boats equal as possible.

We are a non-one-design that sails as if it were one-design because of our interpretation of a "formula" concept. I feel we are growing because of diverse manufacturers while keeping equal footing on the course.

Dan

OK...."Formula" is synonymous with "ingredients" not measurement technique. Formula classes can also employ a box rule, formula, or both for its measurements. 12-Meter keel boats do have materials ("ingredients") limitations for its hulls. So far that works. Looked at the A-Cat ISAF class rules, 3 pages. Page 1 is just a cover page and page 3 are just a few lines. No materials restrictions. Love it!

Right!... but the formula that the class refers to is about crew weight to include teams from 260? to over 400 lbs. (leaving how effective it actually is aside)

This is not what a big boat monohull sailor will think of when we use the term "Formula" in conversation.

Now I'm just dizzy.

In basic terms a box rule provided min and or max values for certain parameters.

A formula rule allows flexibility of certain chosen parameters such that the end combination or formula ends up being equal. For example you may increase length if some corresponding reduction in width is taken into account. In a formula rule class it is possible for a 16 foot boat to race equal to an 18 provided both meet the formula.

Within either case there can be any number of restrictions for things like build materials or any number of measurements required. An A class is technically a box rule with relatively few restrictions. An F18 is also a box rule with a lot of restrictions.

There is a little bit of gray area in the F16 and F18, where the sea lawyers could make their pay, involved with the sail size and plan being changeable with weight or crew respectively. My take is these are fixed values, so still not Formula per say.

I think the F18 class chose "Formula 18" as the name because it sounds cooler than "Box 18". Not to mention "F18" sounds like a fast jet, "B18" sounds like a slow bomber.

So its FB-18, or BF-18?

You could also go the direction of...."Box 18" sounds silly.

I vote for "BMF" 18 or 16.

Cue the SHAFT!

http://www.youtube.com/watch?v=L2cHkMwzOiM

I know what "f" stands for every time one of you finishes in front of me AND I'm pretty sure its not "formula". If you change to "b", don't worry, I'll still have something for that as well and it wont be "box". You, YOU LALB!!!

I'll go back to slept now...

'Shaft is a bad mother- (Shut your mouth)