I posted this on the main forum, but someone here may have the answer.

What rating system is used for large multihulls and does that system allow for them to race with monohulls, either around buoys or off-shore?

For example I have seen pictures of Farrier tris competing with monohulls, even in the Fastnet, and wonder what system is used. Here in the Chesapeake the multihull group has an internal (I think) rating system that doesn't resemble PHRF, which is used for the keel boats here, so I'm not sure what they do when they complete with monos. Maybe they aren't allowed to compete with monohulls for things like line honors...
The US IRC system that is being heavily promoted this year doesn't seem to be for multihulls (the sign up form asks what model of monohull you own). The same is true for Americap.


Are mulithulls getting shut out of amateur off shore racing with these new rating systems? That seems counter to the general trend towards recognition of the multihull's superiority in speed for off-shore distance racing, up to and including around the world stuff.

David