Dave C fitted foils on his A Class cat several years ago and think is the reason for the A Class rule which also states in part that no board may extend beyond the 7,5 beam limitation in a lowered or raised position ,--which in effect means not only no hydrofoils ,but no angled boards which have been proven to be very effective and should be developed further .

Maybe we need the resurgence of the 18 sq class ,-though would like to see an open development 20 class emerge and race events for them to test within .

It seems difficult enough just to get a group of production cats together these days ,-hope that changes again soon, but will only change as new innovative fun high speed sailing craft are developed and made available ,-much as Hobie Alter accomplished in the 70s early 80s time frame - we are overdue for another innovator and innovative design to get new interest.

thanks for the info and link .