When I booked this, it was called the Na Pali Snorkel and Sunset Cruise. I am putting that out there because some of the other reviews I read said that they were not aware that they should be dressed casually. The website specifically listed out that one should expect to get wet, one should wear swimsuits under clothing, or bring an extra set of clothes; it also said that one should bring a bag that was okay to get wet, and not to bring valuables you did not want to get wet. In other words, don't dress in formal wear, and if you bring a camera or phone without some kind of waterproofing, then there is a possibility you will cause damage to that equipment. They even tell you to take motion sickness preventatives beforehand. I wanted to give kudos to Kauai Sea Tours for all of the information they provided before I booked because it's a chunk of money, and their customer service was great at answering all my questions.
By the way, IF YOU GET MOTION SICK EASILY, take a Dramamine or wear Sea Bands, or do both. The surf in and around Kauai is choppier than other islands I have been to (both other Hawaiian islands, and Caribbean islands). This cruise is going to have some choppiness to it, even on the days with the calmest weather.
All that said, for the chunk of money, you get an amazing tour of the Na Pali coast. Our family consisted of my husband, my 14 year old, and my 11 year old (neither of the kids had previous ocean snorkeling experience). The captain and the crew were very upfront in explaining what to expect (there will be some choppy weather, there is a 45-minute stop to snorkel, you will get wet,etc.). The captain also explained safety protocol and options when we stopped to snorkel (you can use a personal flotation device or pool noodle while snorkeling, which side of the boat to stay on, the crew would be in the water to assist, the ways to enter the water from the boat - direct jump, slide in, enter off the back swim pad). If you have family members who have not snorkeled in the ocean before, I recommend doing a buddy system just so you can keep an eye on each other.
After snorkeling, a buffet style dinner was served of rice, salad, rolls, chicken, with cookies offered for dessert. Throughout the cruise, you can also have crackers/salami/cheese and soda or water. The bar 'opened' about 2 hours into the cruise - meaning mai tais were available. There is no custom cocktail mixing to my knowledge.
The captain did the perfect amount of storytelling of the history of Kauai and Ni Hao. The crew were fabulous at answering all my kids' anxious questions. Overall, we had an amazing time. If we had the money to do this every day, we would have!
As an FYI, there was approximately 35 people on our cruise. Two parties were not present at the time of boarding, so I think the max capacity is a little higher. However, with 35 people, there was a lot of room, and we never felt like we couldn't move around unless we were instructed not to during certain activities (docking, anchoring etc.)