Amy and I had planned to go scuba diving in the Reef, as these tours offer introductory dives that give you all the training/certification you need. But unfortunately, I was medically disqualified from doing so. So I went snorkeling instead (as did Amy out of solidarity). This actually ended up being a blessing in disguise, as the first-time Scuba-ers spent most of their time on the training, and had to stay close to the instructor. We had free range, twice as much time, and saw much of the same sea life they did. We'll do Scuba another time.