This is the first time I went snorkeling. When the boat approched the coral reef, it started becoming bumpy, and it became worse after the boat was archored. I got sea sick. All the tourist went off board. The captain (Jeff?) and his assitant (Kate or Kelly?) helped me dealing with sea sickness and spent quite some time coaching me put on the gear (goggle, lifejacket, noddle for extra floating force). After I praticed snorkeling in the water near the end of the boat, I went for the corel reef for snorkeling. The water was so clear, I saw many beautiful fish.
I am very grateful to the crew for their help, which allowed me to enjoy the my first snorkeling trip. We only had about 10 to 15 tourists on board, which was nice, and people were nice. In hind sight, maybe I should have chosen a bigger ship (catamaran ?) which may offer a less bummy ride, given my sea sick experience (I did have a big lunch right before the trip, a big mistake).
I do want to mention that it took me a while to find the boat. I was provided the address of a hotel, there were two locations behind the hotel that offer snorkeling boat ride, and there were no way for me to associate the location with what I purchased. Finally I saw the word Fish Monster in the confirmation message of my order, and I happen to see a small both on the street named Fish Monster, where I was able to get confirmation of the boat location.
If you have not done snorkeling before, try to learn by watching some videos before you go.