I think no rocker is best but some adjustable lift on the bow would be quite beneficial for this kind of proas. I keep returning to Fulgencio Garcias idea of twin bruce foils that adjust CoE of lateral plane back and provide lift to the bows. You can see pictures and text in the files of proafile 1 and 6. However there are serious downsides which I haven't been able to solve so rudders made in Ono style are still my favorites. The downsides of Fulgencio's twin foil solution are 1) useless when motoring and in marinas, 2) cannot be lifted and 3) very vulnerable when hitting the bottom. When sailing Fulgencio's solution would offer the easiest adjustment of lateral area and fastest shunting times but the drawbacks above need to be solved first.   Regards, Arto --- On Tue, 8/25/09, arttuheinonen@heinoset.net <arttuheinonen@heinoset.net> wrote: From: arttuheinonen@heinoset.net <arttuheinonen@heinoset.net> Subject: Re: [harryproa] rocker vs straight hull shape To: harryproa@yahoogroups.com.au Date: Tuesday, August 25, 2009, 8:16 AM   Hi, I also think that no rocker is the best for our purpose. I just had to think about it once more when I read what Mr Erik Lerouge wrote about hulls and foils. I respect him very much as a boat designer. Yes, Ono is our boat. I think ww hull without rocker is probably better for cruising program because it has more displacement. I f you can ceep ww hull light, some rocker is probably better. First I wanted to have more weight on the ww side. Now I am going to move our 100 litre water tank and all extra stuff inside lw-hull to make ww side a bit lighter easier planing . Also going to build a pair or daggerboards. I really want to have the autopilot too. Rudolfs Jefa bearings look nice.... Regards, Arttu > arrttuu, > you build the ono? > how is it's rocker? > seemes better for turning n]maybe. > > when going straight line - should be flat bottomed. > Doug > > --- On Mon, 24/8/09, proabuilder <arttuheinonen@ heinoset. net> wrote: > > From: proabuilder <arttuheinonen@ heinoset. net> > Subject: [harryproa] rocker vs straight hull shape > To: harryproa@yahoogrou ps.com.au > Date: Monday, 24 August, 2009, 10:52 PM > > > > > > >   > > > > > > Which shape is better for lw hull? > > Many people think a hull is faster without rocker, as on trimaran hulls. Many racing trimarans have rocker on main hull and straght side hulls. > > But... straight hull does not give much hydrodynamic lift when the nose is pressed as well designed rocker hull does , or does it?? > > On a proa to have some hydrodynamic lift on forward of the mast would be an advantage, or would it? any comments. > > I am not 100% convinced about having main hull without rocker. > > > > Regards, > > > > Arttu > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >

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