[billsreef]

In the days before dive tourism was as big as it is now, Cozumel was considered an advanced level dive location due to the currents. By all means it is best to get certified prior, and even better get a bunch of local dives in to get comfortable. Might be only lake dives, but even that will help. The idea is to be very comfortable under the water. The currents in Cozumel make for some very good drift diving. Lot's of fun and good sights.