I have two idea's with respect to this.

First I've run the math on a boardless design. Without going into mathematical details I garantee that the boat will steer and tack significantly easier and quicker by going to a shorter hull length. Disproportionate easier.

To give an example a 12 ft boardless cat with a deep V-ed keelline with tack/steer almost twice as easily as a 5 mtr. long boardless cat with a deep V-ed keelline like the Hobie 16's and Prindle 16's. That is a huge difference.

Bascially this results comes from the fact that the points of the hull furtherst away from the fullcrum contributed disproportionally to the "tacking/steering" resistance. This is aggrevated by the fact that fluid resistance is quadractically dependent on the speed through the fluid. Of course the bows on a 12 ft hull travel much faster sideways through the water when steering then the bows of a 16 foot hull. The difference being 35 % in speed and therefor result in 135*135 = 183% in drag force alone. Then of course the leverage of the shorter hull is less as well. And like that things really do add up.

Currently I'm going on the expectation that these effects will make the boardless F12 steer easily enough without the need to have daggerboards.


However when a need is found then the vertical sides of the hull will allow an external pivoting boards to be fitted on the inside (or outside) of the hulls. Just a simple bolt going through the head of the board and through the reinforced wall of the hull. With transporting or hitting something the daggerboard will just rotate to a horizontal position alongside the hull.

However, looking over the specs at this time I'm really not convinced that a daggerboards will add much benefit to the design. The line of think here is that that rig is relatively small, its overall area is disproportionally smaller the wetted surface area of the hulls are. The latter is fixed because of the need to carry the given combined weight. Basically you have all that area almost vertical in the water that also wants to resist sideways movement. Now any movement resisted by the hull will deteriorate the benefit of adding a daggerboard as the daggerboard needs some sideways movement to get at its optimal angle of attack of about 2 to 4 degrees.

So we are faced with a fork in the road here. Either we go for daggerboards and then we want the keelline to be as flat and rounded as possible with all related increases in denting and risk of damage. Or we go for the multichined hull that is very resistant to damage and much more easy to build and go for a boardless design. Combining a multichine hull with a daggerboards will mostly deteriorated the strong points of either to a level that may make either negligliable.

Wouter