Rick,

With regard to Paul Larsen's craft: I'm aware of the points you make. The foil was the biggest problem.  A lot of stuff happens around 50 knots (and Mach 1) that the average foiler doesn't have to think about.  The semantic issue was calling it a planing craft, when its a 3-way hybrid.  And it foils.  Up or down doesn't matter.

Thanks for the info on the 18 m and its foils.  Interestingly, the radius on the last section I modelled is 4mm - assuming 400mm chord.  The latest tweaks have seen the foils operate between +- 3.3 degrees with greater than -0.8 Cp.  The next step, and I'm going to be awol from this forum while I do it, is to add a foil design routine to the CAD boat design package I wrote.  Might only take a few hours (famous last words).  This will enable me to tweak shapes faster and in far greater number.

Citing Banque Populaire as an example for slamming minimisation is all very well, but most people budgets don't go to that length.  And hulls this slender are not planing.  Though perhaps we are using terms differently.  Slender hulls simply push through the drag hump associated with hull speed.

As for VPP.  I wrote my own many years ago.  Does all the aerodynamic calcs and produces graphical polars.  Hydro drag must be plugged in as a formula.  VPP will be done alongside the foil engineering.  Foil section calcs don't determine all the parameters I require.  I'll look into available software as I'm not stubbornly wedded to my software.

Foiling operating range can be accommodated by surface piercing or ladder (T or V) foils.  And the foils will most definitely lift clear.

David

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