I booked the snorkeling trip for three and I was just going along to watch. My 13 year old son decided he didn't want to snorkel; so I asked if we could both be dropped off at Boca Chita Island instead. No problem. They also put the $10 diference between the the snorkeling trip and the Boca Chita trip toward a wetsuit! They didn't have to do that, but I appreciated it.
We didn't see anything in the water on the trip (except while snorkeling of course), but there were a lot of birds. They even name the regular birds. The snorkelers had a good time and saw lots of fish and coral. My 16 year old swims but she's not a really strong swimmer. She did fine. The trip was well done.
All of us had fun on the trip, snorkeling and not. It's a good option to do two different things if not everyone is up to snorkeling. It's nice that both trips go out on the same boat. Biscayne is a great National Park, but it's hard to appreciate it because it's mostly in the water. The trips that Biscayne National Underwater Park offers allow you to see a little more.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.