Great regattas are large professionally run events with good people (both your competitors and the regatta support people), good venue and good wind.

well run racing, good turnout, good food, good facilities are all assumed in the above statement.

Newport Regatta comes to mind. I'm not sure if they have a catamaran class this year, it might be an opportunity for a beach cat class to participate in an excellent regatta.

The HT class did the Newport Regatta for 2 years and it was excellent. We paid to have Randy Smythe come and give us a clinic one year on the Friday prior to racing.

The races committees are top notch. The venue is extrodinary, right on the lawn next to Newport Sailing center, Sail Newport, the spot of the ex Newport AC bases. The town of Newport ranks right up with Annapolis as the hot sailing spot on the east coast.

If you can get your class invited it would be well worth your time.

http://www.sailnewport.org/npt/m/_general/05volksreport.asp

If you want to know what great is, I suggest you check out this one.