Book with another provider. The transportation was poorly coordinated, we snorkeled at two locations for about an hour each and did not include El Cielo. The equipment provided was substandard including cheap inflatable safety vests with snorkel gear of questionably hygiene standards. The food was sparse and the buffet lunch had a long line with no seating, which didn't matter because the food was in edible even though I was starving. The place is beautiful and staff friendly but this company was a mistake.
The provider promotes this as a snorkel tour. In fact, it is for both divers and snorkelers - their name is Pro Dive Mexico. Of course, you do not know that they are a dive company until you book. And even then there is no indication that you will be paired with divers. A dive tour and a snorkel tour have clearly different objectives. Our trip had 7 divers and 7 snorkelers. But 3 of the snorkelers were related to the divers, so they were there for that reason. Our party of 4 was the only group interested in snorkel only since we booked a snorkel tour. The only other review on viator was from a family that had their own tour and thus got to snorkel at shallow reefs.
The tour went to two reefs one 20 feet deep, one 50 feet deep. They skipped what their board had listed as their snorkel reef Columbia Shallows. So basically, the reef was in accessible. Also, door to door the trip took 11 hours. Once they get you to Cozumel, you take an hour long boat ride to their shop. And after the trip, an hour long boat ride back to the ferry. Long day, expensive day, very few fish and none within 20 feet. They took no blame for our experience. However, Viator stepped up to the plate and made it right.
I would avoid this tour, unless you like fish very far away.