Don't let the drift diving scare you about Cozumel. I am a new diver and it is a little different but not any harder. Be honest about your experience and air consumption with your dive shop, I hate to be the one that makes a group come up much earlier than the need to.
I did the CUN to Cozumel "bag drag" in October and it was not bad at all, plenty of info on here and Trip Advisor.
Never dove on Isla Mujeres but stayed there for a few days and it is much more conjested than Coz. No cruise ship traffic but many day tripers from Cancun. Talked to a guy fgrom San Pedro Belize there who was selling stuff on the street and he said there was many more people there than in Belize. Don't go to Isla Mujeres for peace and quite.
I did the CUN to Cozumel "bag drag" in October and it was not bad at all, plenty of info on here and Trip Advisor.
Never dove on Isla Mujeres but stayed there for a few days and it is much more conjested than Coz. No cruise ship traffic but many day tripers from Cancun. Talked to a guy fgrom San Pedro Belize there who was selling stuff on the street and he said there was many more people there than in Belize. Don't go to Isla Mujeres for peace and quite.