Tom Speer has posted a lot on the International Hydrofoil Society website, and is a real aeronautical engineer working for a large aircraft company in Seattle. A cut from the site (that Carl says looks dated) is copied below.
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!

Source of Foil Profiles (Tom Speer answer)
[3 May 01] I am part of a group of students engineers that studies l'Hydroptère. I look for the view of the profile EPPLER817 that we used to realize the foil of our maquette. In particular, I do not find the curves Cz and Cx incident to this fine profile. I am therefore very appreciative if you could help me in this area) -- Elie Daguet ([email protected])

Response...
[3 May 01] The data may be found at www.nasg.com/afdb/index-e.phtml. There you'll find data for the following hydrofoil sections:

Eppler E817(E817)
Eppler E818(E818)
Eppler E836(E836)
Eppler E837(E837)
Eppler E838(E838)
Eppler E874(E874)
Eppler E904(E904)
Eppler E908(E908)
Speer H105(H105)
The most complete database of section coordinates is at the UIUC Airfoil Data Site. With the coordinates from there and XFOIL (http://raphael.mit.edu/xfoil/), one can generate the data for precisely the conditions desired. -- Tom Speer ([email protected]); website: www.tspeer.com; fax: +1 206 878 5269