Having stayed at BA several times and also using the BA Dive Op, getting tanks for free shore dives is simple. You grab one of the many that are lined up right outside the dive shop and go diving! I guess if you want a nitrox tank you can take one. You can always email or call them and ask if you are really interested. As I recall, most of the tanks are nitrox anyway. I don't do a lot of shore diving in Coz. BA has a nice "pen" right out front for training dives. They have a buoyancy & trim obstacle course setup as well. If you need B&T practice it is a great place to do it while in Coz.Nothing is for FREE. Shops that are charging you $10 - $12 a tank for nitrox are making big profit. Consumers need to look around these days. Lots of options in Cozumel especially during low season. Does shore diving include FREE nitrox?