Dive Club Planning trip to COZUMEL

[DanL]

Wade is right - El Coz is good, and travel through worryfree vacations or apple vacations gives you good deals with a range of prices depending on the hotel options.
One thing to keep in mind - El Coz is on the N end of the island, and most of the marine park and dive sites are south of downtown - some very far south.  So for diving, you might want to pick a hotel somewhere south of downtown - nearer the Caleta marina where most dive boats are docked.