I feel fortunate to have chosen Wavelength for my first snorkeling adventure in the Great Barrier Reef for a couple of reasons. First, they never take more than 30 people (however yesterday there were only 25 in our group) and second they did a superb job of swimming with you to explain what you were seeing. Half the time I followed the guides and the other half I spent exploring on my own. The tour stopped in three separate locations for an hour each time which may sound like a lot but the time absolutely flew. Thanks to the wet suits, I avoided getting a painful burn.
I know that many people suggest SCUBA diving when visting the GBR but something we learnt on our tour was that 85-90% of all marine life that you would want to see lives within the first 5 - 10 meters (15 - 30 feet). This is because coral needs to be able to absorb the rays of sunlight to flourish and the sea life relies on the coral in turn so if you can hold your breath for a minute or two, one can swim to the floor of the reef and see all there is. Even for those who were not comfortable like I was - the water is so clear that it is quite easy to see the marine life while floating atop the water.
The only down side to the entire experience was for Sergio who despite taking the sea-sick pills the crew eagerly encouraged everyone to take, was not feeling great by the time of the 3rd stop. The 1 hour+ boat ride back to shore had Sergio a strange shade of green.