In this post I wish to reply to the points made by others.




The 3.66 mtr hull will only be 0.555 kg = say 0.6 kg lighter then the 3.90 mtr hull. I worked that out with the design software. So in total the longer is 1.2 kg heavier overall. So this can not be a major point.

Making the hulls wider is a solution to getting the weight carrying ability both together with the severe limits on the sail area that can be carried because of pushing the bows under it will be slower then the Hobie wave and even the laser 1 dinghy. That are serious considerations.





The boat will never be build out of less then 2 sheets of ply. An additional sheet of ply is less then 50 Euro's including taxes. The difference in area between the 3.66 and 3.90 is 0.157 sq. mtr. per hull. That is 400x400 mm. This suggest that unless the 3.66 only just fits into 2 sheet then the 3.90 can be made from 2 sheets as well. I think both can be made out of 2 sheets, but a more in depth analysis must still be made here. But for an additional 50 bucks (shipping is already paid on the other 2 sheets) I don't think having to use a 3rd sheet is any serious obstacle.






My objective to have a design that can also be sailed by teenagers and small to medium adults and not only kids. The reasons for this is that kids grow into teenagers and adults and they won't rif the bike with training wheels for more then 2 years either. Also it is must easier for a parent to justify buying / building a F12 is he (she) can sail it himself as well. Additionally I want to be able to have kids sail the boat doublehanded as well. And I would really love to see this boat being sailed on an apparent wind policy. All these points are much better serviced by 3.90 then 3.66 mtr.

With respect to comparable to F18's and F16's, you misunderstood my point here. The F12 is not, with the possible exception of teaching sailors apparent wind sailing. What the comparison to f18 was intended to show is that a 35 and 50 crew on a 3.66 mtr F12 will perform relative to eachother as an F18 sailed at 115 kg and 180 kg. Meaning that even relatively small weight differences in the F12 will result in performance differences quickly. This is not something older kids and teenagers will appreciate very much after they learned to sail it. Young kids may not care at all but when the grow up in only a few years then they will care. At 3000 US or 2300 Euro investment the F12 better be succesful in keeping the kids interested for more then 2 to 3 years.






Different style of rig and as of yet I'm not using skegs on the hulls. This F12 is much more like the Supercat line of boats (like SC15 and SC17) then skeg boats. Without the skeg the hulls should tack noticebly better. Additionally my F12 isn't using sharp V-ed keel lines, it is much flatter on the keel. The rig will move forward when releasing the sheet and move back when sheeting tight. In effect the load on the rudders will be less during a tack when the sheet is released. The movement is the result of the flexing of the mast and not of any mechanical setup.

Currently my version of the F12 doesn't have a trapeze and I'm not looking at adding one. This makes quick tacking alot more viable thus spotting shifts and tacking is a more serious consideration then on a larger cat.

Ultra low profile boards are called skegs I think. But indeed short permanent stubs can put on the keel. Running a ground is not a real problem as short stubs will be very strong. But as of yet I want to try the no skeg or stubs approach. Afterall the Supercats aren't regarded as slow boats.





I sailed several hobie cats that had them. The Pacific (rip-off tiger) was aweful to tack. The shorter versions like the Dragoon where actually quite alright in tacking.





The paper tiger is long still and by much more then the 3.90 is longer then the 3.66 (compare 240mm to 370mm). But the F12 I see it is not so much different in the hulls but in all other things like the rig and the dolphinstriker less mainbeam, not having stays and the sleeved sail. As such it will always be much different (and I suspect much simpler as well) then the paper tiger and Arrow. Afterall the Paper tiger is also a VERY technical boat to sail with the baby stays and such. I don't think your comparison does justice to what we are really looking at here with the F12.

Adding a trapeze involves alot more then just adding a steel cable with a handle and ring. Most inmediate result will be that the mainbeam will have to be fitted with a dolphinstriker setup. And more volume needs to be moved to the bow to prevent the boat from pushing its bows down under the increased sail forces. In effect having a trapeze on the 3.66 mtr hull is having the worst of both worlds. I'm not writing off the trapeze completely but there are a few very serious points arguing against it. One of which is my own experience with the Hobie dragoon. At 80 kg I couldn't trapeze as it would immediately put its bows in. To kids at 40 kg trapezing would have nearly the same result. Also the trapeze is serious obstacle to quick tacking on shifts (coaching ?). I'm far more interesting in making the boat a little wider then adding a trapeze. Also we musn't forget that the F12 sails are much smaller in area and luff length. It will require alot of wind to even have to trapeze.


Wouter