Trimarans? I heard that from the founder and director of the Formula 14 class. And I do not see how they are incompatible with catamarans. They raced against each other in the Formula 40 Class.

Foilers? As far as sailboats, I see those as a completely separate, new classification that encompasses sailboards, monohulls, catamarans, and trimarans.

Foilers are at least as different from multihulls as multihulls are from monohulls. In essence, foilers bring all of the sailing boat types/hull types together because they all start being more equal once you get ABOVE the water. It is a whole new dimension with its own experimentation going on. They do not really belong in any specific "water-locked" sailing class, formula or not. In fact, I think that trying to fit into an existing class would inhibit the development of the foiler technology.

Add: In fact, foilers are kind of like sailboards in being a separate classification.