DjDiverDan
Contributor
First, a friend of mine who is now a freelance DM on Coz, Miguel Estrella, who you can email at estrellamiguel6@gmail.com. Miguel was a Dive Master with Dive with Martin for many years, and I’ve been diving with him a number of times - I highly recommend him, he’ll be able to show you the little stuff on the Cozumel reefs that you would miss on your own, like the Cozumel Splendid Toadfish, only found in Cozumel. That’s his photo above (we were having lunch at Pescaderia San Carlos, which, BTW, I also recommend). You can search for him on Facebook and find his phone number. As a freelancer, he knows several boat captains who might be able to set you up.
Second, Dive with Martin, an excellent budget end Dive Op. They might be able to do a charter with only 4 people for an afternoon dive/snorkel trip. Check with them on pricing.
Third, any of several highly recommended Dive Ops mentioned here on Scubaboard, I think I’d start with Christi at Blue XTSea Divers.
Good luck.