We had a perfect day!, you go in the trip with one captain who is explaining you about dolphins and their costumes and life. The member crew explain about snorkeling and offer us a lot of drinks (included in the price) during all the trip.
The coral barrier is not as beautiful as others, and you will make de snorkle by your own, no one is on the water with you, but they keep an eye in everyone from the ship.
We did it with three children and they enjoyed a lot. We also had a lot of fun!