F18 always used to allow canted hulls; if they don't now that there must have been a recent amendment that I missed. I don't think such a change to the rules was made though. Canted daggerboards is another matter, these are forbidden in the F18 rules if the baords are under an angle relative to the centreplan of the hulls. In effect your boards must have the same canting as your hulls.

However most F18's have gone back to uncanted boards as there doesn't seem to be much advantage to having canted hulls.

Wouter