We went to Tunnels beach, but were warned in advance that going during the winter/early part of the year it can be a bit rough. We were there in mid-March. And it was. Maybe we didn't find the best spot at Tunnels, but we spent a lot of energy just trying to get around and fight the subtle currents. I liked Lawai Beach in Poipu much more. I was told by the person at the snorkel rental that she considered Lawai Beach as the best Kauai snorkeling. But again - it might be related to time of year.