We are sailing on the Conquest 7/26, and a couple of people in our group are going to try it. Evidently there are 2 locations on Cozumel to do this. We are going to be doing the Dolphin Discovery at Chankanaab Park, and one of the Sea Trek locations is there also, so we are booking direct with them. The cost is $59, so quite a savings. I think it will be a fun adventure for those doing it (not me, I'm too claustrophobic!). Chankanaab Park is a 15-20 min. cab ride from the pier.