On the subject of simple fast build hulls, this is something I put together this time last year, never got round to making it, maybe I will this year. The idea was a 10ft boat hull that could be built from a single sheet of 3m x 1.5m ply, it could easily be scaled up to an F12 , in fact I have a parametric CAD program that will produce drawings of any size you want.
The hulls are asymmetric and shouldn’t require a daggerboard. The nice thing about it was the minimum amount of cutting required to make the panels.
The attached PDF file is a hull template that you can print off and make yourself a model. The two sheets contain identical panels, just layed out on the sheet in different ways. The first sheet is meant to show that the same cut produces both side panels, i.e. two sets of side panels (for two hulls) can be created with just 5 cuts instead of the usual 8.
The second sheet is to aid model building out of a material that can be folded such as card or paper i.e. the three horizontal lines in the centre of the panels should be folded not cut. All the panels are flat with the exception on the four outer leaves of the side panels which require some gentle bending.
Print it out and try it http://4hulls.googlepages.com/flatpack3.pdf