My wife and I took a Na Pali coast excursion on the Kauai Sea Tours "Lucky Lady" boat out of Port Allen, about 5 years back. It was more like a motor catamaran with a decorative sail. Even it had a tough time plowing through some of the waves on the south and west sides in August. But then again, there are tours that go out all the time in RIB's. That's why I thought those people might be a good source of info on where is good and where to avoid. (Whenever I talk about quitting work, I say I'm going to move to Kauai and be the guy who holds the barf bucket for the tourists on the Lucky Lady.)