Not too far away is a Dressel Divers - think it's the Iberostar Quetzal. I dove with a Dressel that was located farther north, but still considered PDC, a few years back. I mention them because they pickup/dropoff and do have daily (except Sunday) trips to Cozumel.
If like with me, the routine would be, get picked up at hotel, go to their dive shop for gear/pick up other divers, transfer to ferry, get picked up by boat at Coz pier and go to their dive shop located at the Iberostar (but right there in the Marine Park), do a couple of dives, we were given an AI band so were able to eat/drink before and after the dives (although there wasn't a lot of time), ride boat back to ferry, ferry back to PDC, someone waiting to take us back to Dressel and then our resort. Whew!!! All was included in a pretty low price - we actually did a package of 11 dives, which included 2 cenote dives and a night dive, just in case you're interested. If you're only diving 1 day, the biggest issue may be that you have to book in advance on their website - it's not hard, but might seem strange just to book a dive.
I'm slowly updating my spreadsheet (I'm going in January) that
@Rob9876 referred to (thanks for that.) Dive times aren't really changing, but some prices are going up and some have come down. I show how far away the dive ops are from the ferry pier as well as dive times of the ops. Best to contact possible ops (I provide the link) and see when and where you would need to be.