Those are my pictures!!! I added an F18 chute to my former H17 and it worked perfectly. However, I never sailed the spi with heavy wind and am not sure if the mast would hold up. On the other hand, I think that if you apply some downhaul and lots of main sheet it should be ok up to 10-15kts...

Tony
Hobie FX One #104
Tony@Hobie17.com