Peter,
Check out the forum on this website for the Hawaii Hobie Cat Association (HCCA), down below the Multihull Council forum in the main index. Posts by Dray and Chrismargaret.

They do seem to have regattas and are trying to generate activity, although this particular forum has not been very active for the past two years. I don't know whether there has not been much going on over there or whether they are just not using this forum much any more. At any rate, Chris and Dray are two good contacts.