We almost always use independent operators that have been recommended by other cruisers. If you are going to Grand Cayman, I highly recommend the Buccaneer
for a great excursion to Stingray City. We LOVED this excursion! The timing was perfect, and we got to go to 3 stops. Also, there weren't a lot of people on our excursion! Check out my photos to see some of the fun we had.