...Eppler 817 and Speer's foil shape H105 are PROBABLY best for hydrofoil sailing: These are low rise, low bucket shapes that should not ventilate readily at our speeds. Caveats: Supercavitating foils and/or air injection are for high-powered motor-driven vessels only. Sharp entry symmetrical foils like the NACA0012 series ventilate readily. I know this for a fact!...
FYI, here are the cavitation diagrams for the E817 and H105 plus a NACA 6-series section. These data are not found on the NASG site.
![[Linked Image]](http://www.tspeer.com/temp/Cavitation.gif)
Ventilation, of course, is a different animal. You need to have separated flow to cause ventilation, so that may be a good place to look. I don't know why the NACA 0012 would be particularly ventilation-prone - I'd expect it to be more resistant. But maybe there were some details of the actual foil configuration that caused the flow to separate.
