Snorkeling/Sailing/Boating w/maybe El Ceiba?

We are a small group of friends visiting Cozumel by cruise ship in a few months who are trying to find a nice, not super crowded excursion to snorkel, have some snacks and drinks, and hopefully stop at a beach for while. El Ceiba could be included but it's not a mandatory stop. We don't necessarily care about having a "wild and crazy" experience with a huge emphasis on booze. Initially we hoped to find a catamaran or a really nice type of boat excursion. We did find a catamaran (Tucan) but it is booked the day we need it. The other excursions we have found all seem to visit El Cielo and offer snorkeling and contract with independent vendors. It's tough to tell what type or size of boat we'd be getting or know anything about who will actually be taking us.

As for the companies that contract out with various vendors, which one(s) offer the best experiences and are the most reliable to deliver what they promise?

We could really use some recommendations, please!