If you have flexible booking schedule, ask for Quintin or Ian. We had both on our tour and they were both great tour guides, both knowledgeable and friendly and willing to share and gab. They made the tour really excellent. The tour motors north to the Na Pali coast, reaches the north end, and sails back south toward their snorkel spot which is a beautiful reef where the fish are plentiful as long as the food lasts. After that they're sparse at best. (There are better places to snorkel on Kauai). After snorkeling you're fed a mini buffet style meat and cheese sandwich and pasta salad lunch as you move slowly back towards home. After lunch the captain picks up speed and you get a more adventurous (read: wet and bumpy) ride back.
We saw gorgeous coastline, spinner dolphins, sea turtles, a few types of fish, naval training grounds (from a distance), and the remains of sugar mills.
Advice: If you're prone to seasickness, take something before you board! Don't think you'll wing it. Several people lost it during the trip which only made the bathrooms really hard to use for the rest of us. Also, take extra beach towels and keep some dry. The ride back gets really wet, unless you're inside. So you'll need towels for after snorkeling and for when you arrive. You might also want to take water just to rinse off the sea salt after you get back. THey lend you snorkel gear, but take an underwater camera and maybe fish food.
