Mary, while getting kids started when they are young is important, I believe the formative years of sailing begins when parents begin to let their kids enjoy sailing on their own and unsupervised, which is probably somewhere around 12-13. My fondest memories of sailing in my youth were when I sailed out by the harbor entrance and routinely capsized our Flying Junior jumping and riding waves. That is where my real love of sailing began. Even then, I wanted more speed and I recall asking my dad if we could build a sailing proa (remember Crossbow?) which sounded thrilling. It would have been a thrill to have built a cat like this F12 with my dad.

I must confess, I like what Wouter is working on, whatever it’s called. It may be a little on the expensive side, but if its construction is truly short & simple, it may be well worth it.

This may be a crazy idea, but can we have two classes – a F11 & F12?

Wouter, not that I’m asking you to design it, but would it be possible to build an 11 foot cat that would meet the objectives Mary laid out – or is 11 feet just too short? If it was possible, the F11 could address the younger kids at a low cost & lower performance, and the F12 would address the teenage market - which I believe is important.

Bill Nieuwkerk

Bill,
Yes, actually, I would prefer 11 feet or even 10 feet -- the smaller the better (except for the problem with weight-carrying ability) -- because my belief is exactly the opposite of yours. The formative years start MUCH younger. By the time they are 12 or 13, they have other interests and activities, and you have lost them.

Kids need a boat they can singlehand when they are 7 or 8. That is why I have always said they should be started out in the Opti -- besides the fact that it is easier to learn on a monohull, it is very empowering for a young child to be the master of his or her own vessel. So let her take a few lessons on an Opti at the local sailing school, and then put her on the little cat

When they get into pre-teen and teen years is when they want to sail with friends, so it is important that they already be seasoned sailors by the time they get to that point.

P.S.
I was looking again at the pictures of the Arafura Cadet, which is only 11 feet, and that seems like it would work for all the age ranges.

I really agree with Mary, hook them while they are young and you keep them for life, as certain industries have proved. I also envision a 12 footer as a boat for the youngsters, as an alternative to the Optimist. I dont agree at all with the notion that youngsters should start out in the Optimist. Why send them trough such an experience? I dont understand why it is "easier to learn on a monohull"?

When they grow larger, the F-16 could be the next logical step (?).

I also agree with Mary and Rolf, there are allready a bunch of suitable cats for teenagers, but not for youngsters. So why bother with yet another one.

I think the 12ft F12 is a great idea for my 3 chidren age 5-10 (I'll leave the 7 month out of this discssion). They have an Oppie but I feel there are many advantages in a cat not least the greater stability.

I thought this is where the dscussion started and it then drifted toward a higher performance cats that could also be sailed by a lightweight adult. For which I see no need.

Gareth

Everything is possible, but the F11 would only be slower, not cheaper.

That is a concept that is not understood by several in this discussion. A rudder setup for a F12'10" is just as expensive as a rudder setup for a F10. Same goes for the ply used and the sail and the blocks used etc. Cutting the mast down from 6 mtr. to 4.5 meter will not save much money if it saves anything at all. You still have to buy standard lengths of tubing. If a F11 platform still needs 5 sheets of ply, same as the F12'10". The only difference is that at after the building is done you are left with more waste.

You guys are thinking far to much along irrational lines. Price is not always proportional with size, most often the prices changes with jumps like when an additional sheet of ply is needed or when the mast is longer then can be shipped using normal procedures. Going smaller therefor does not often make a product cheaper if the orginal setup was already making use of the cheaper setup.

The only real draw back of F11 is that you are both reducing overall weight (bouyancy) and hull length (pitch leverage) meaning that the sail area you can carry will reduce more then the length of the boat. And if you don't do that then the craft will be noticeably more difficult to handle or control in any breeze. Neither of which is very attractive in giving a well behaved craft to young children. And chances are that you'll spend just as much money.

So summarizing : same money investment, much less performance and worse control behaviour if you are not careful.

Wouter

Ok, that leaves two questions on the difference between 12'10" and 12'.
What will the weight difference of the complete package be (and what weight will mum have to lift on to the roof of the car) and what will optimum crew weight for the two different lengths be?

I recall (in the 20 or so times I've re-read all these threads) 0.6kg per hull difference between 3.66 and 3.9m length.

I just re-read the post about crew weights yesterday, and he said for the smaller boat the crew weight would range from 31 to 50 kg, with 43 kg being optimal.

For the bigger boat, crew weight range is 49-72 kg, with 63 kg being optimal.

Keep in mind that only applies to his particular design and is not necessarily true of other designs. It sounds like the Australian boats carry a lot more weight than that.

0.6kg per hull.. Well if that is the case the weight difference is no big issue. How about minimum crew weight to handle the boat? What would the difference between the two "proposals" be there?

Not necassarily only with a certian hull shape, it will be harder to aheive the same pitch resistance granted but....

Also you can change the aspect ratio of the sails, to give you the same pitch resistence for the same sail area. There are lots of things you can do.

The same argumant you are using to extend 12 to 12'10" can be used for going to 13' or 13'2" etc

I am interested how many sheets of ply do you require to make your F12 design.

Gareth

Grob

Wouter just answered that up a couple of posts....

"If a F11 platform still needs 5 sheets of ply, same as the F12'10". The only difference is that at after the building is done you are left with more waste."

Well if thats true then this is one of the disadvantages of an 12"10' boat as you can get two hulls for a 12" boat out of just 3 sheets of ply. So you are saving 2 sheets of ply and a whole bunch of cutting.

The reason being is that (as has been said many times before on this forum) You can get 12ft length out of 1.5 sheets of ply (3mx1.5m).

Gareth

I've only came across 2.5 x 1.25 mtr and 8'x4' ply sheets. And so that is what I used in my 5 sheet quote. This is the very reason why a Timber Taipan is 4.96 mtr long instead of 5.0 mtr.

If 3.0 x 1.5 mtr. are available then the F12'10" can be build from 3 sheets as well.

Listen up guys. Don't wander around with your eyes closed. The difference between 12 foot and 12'10" is ONLY 10 inches ! For the longer hull you only need 0.40 sq. mtr more ply in total = ONLY 6.5 % more ply. That is not a big area AT ALL.

And I've been telling you many times before. There will never be more then a single sheet of ply difference between both design. As the shipping cost will remain the same and such the longer hull is at the very maximum 50 Euro's more expensive. That is IF the 12 foot hull can be made using one sheet less, which is really doubtful as the difference in material usage is so small (6.5 %).

Is this really so hard to understand ?

The difference between 12 and 12'10" is by far too small in the areas of costs, weight and of ease building to matter.

But it isn't too small to matter in the areas of performance, dive resistance, control and sail carrying ability.


Wouter

Please show me your math grob...
Based on Johns cad drawing posted on the other thread, which everyone seem to like for the most part… the 12'-0" F12 you would need
4 Pieces 12-1/2"X 8'-0" for the decks
8 Pieces 14” X 8’-0” for the hull sides
8 Pieces 7-1/2” X 8’-0” for the bottom panels.
2 Pieces 12-1/2” X 8’-0” for two bulkheads per hull and the transoms.

Now lets just forget about the fact that all these pieces have to be cut in one piece from a 4’ wide piece of plywood for now…which is a huge issue…lets just add all the pieces together
4 X 12-1/2” =50 inches
8 X 14” =112 inches
8 X 7-1/2” =60 inches
2 X 12-1/2” = 25 inches
247 inches Divided by 48” = 5.14sheets
49-7/32” =5.02 sheets
Even giving you the fact that you will save material by nesting the parts, you will need most of that just to get the boat cut out of five sheets.

Some are saying we will keep it 12’ so there is only one joint between the 8’ panel and the four foot panel…did you forget about the 7X the thickness for the scarf joint? Lost another 13/16, and another 1/8” for the saw cut when you cut the panel in half to get the 4’ long pieces…and then there is the curve in the bottom and the sides, both of which will shorten the overall length, the most drastic curve will dictate the length of the boat…so now we are a couple of inches shy of 12’…oh but we can go thru the trouble to scarf the plywood again to add that couple of inches back on, but it was too much trouble to scarf 10” ….

I will say if you are using metric plywood the length will not be an issue, since it is slightly longer at 49-7/32” X 8’-2”. For those of us in the US, going to Home Depot for common exterior plywood (not recomended), you will definitely run into this problem.

If one would step back and look at the benefits objectively, they would be hard pressed to come to any conclusion other than to go for the increased length.

Regards,
Bob

To a 7- or 8-year-old child do you know how BIG a 13-foot cat looks compared to an 8-foot, pram-nosed dinghy? Even a 12-foot cat is kind of pushing it for the little kids. I'm trying to keep an open mind about it and am willing to experiment on my grandkids to find out whether a 12-footer is too big.

Maybe children are bigger in the Netherlands. My two oldest grandchildren only weigh about 60 pounds each, and the oldest one just turned 11. Most of the kids we know are pretty skinny.

My step-grandchildren include a 17-year-old boy who weighs 135 lbs and a 15-year-old girl who weighs 110 lbs. They both know how to sail but are too involved now in all their other sports activities.

Maybe I am just not thinking "heavy" enough. <img src="http://www.catsailor.com/forums/images/graemlins/grin.gif" alt="" />

"My step-grandchildren include a 17-year-old boy who weighs 135 lbs and a 15-year-old girl who weighs 110 lbs. They both know how to sail but are too involved now in all their other sports activities."

When my son was in high school one of the kids on the sailing team (420s) was 14 or 15 years old 6' tall and about 205lbs...He was the youngest guy on the team, and one of the best sailors on the team. Kids come in all sizes...a slightly bigger platform would help keep the bigger kids in the mix.

Remember if it’s a formula class you can build a boat tailored to your Childs physical characteristics. If 12'-10" seems too intimidating you can always built one 12'-0" or even smaller... But if the platform limits are set too small some of the bigger and/or older kids might not get a chance to participate.

Regards,
Bob

Going back to the US weight and stature for age charts.

Mary,
The 17 y.o. boy and 15 y.o. girl are both at 37 and 40 percentile (compared to average)

Bob,
WHAT THE HELL WERE THEY FEEDING HIM? At age 15 (high side) he was well off the chart for weight and at 96 percentile for height!

The 11 y.o. young lady I'd like to have sail this boat is at the 80 percentile for weight (100 pounds)

And round and round and round and round and round we go !

Wouter

Boy ain't that the truth <img src="http://www.catsailor.com/forums/images/graemlins/smirk.gif" alt="" /> I was just trying to man the battlestations for awhile <img src="http://www.catsailor.com/forums/images/graemlins/smile.gif" alt="" />

"WHAT THE HELL WERE THEY FEEDING HIM? At age 15 (high side) he was well off the chart for weight and at 96 percentile for height!"

He was a big kid...not a fat kid...his dad is 6'-6"

As far as those weight charts...I think some of those lower weights in the "normal" range look more like heroine sheik...

Regards,
Bob