First Dives - Cozumel & Grand Cayman - Expectations?

[Puck]

My buddy and I are both recently OW certified. We decided at the last minute to book dives during port days on an upcomming cruise. Booked through the ship, understaning that this was not going to give us a good a dive as booking ourselves, but it is not like we won't be going back for an extended dive trip in the future.

My question is: what can I expect on the dive boat -- the logistics, service, etc. What happens before and after the dive, and how will rookies like us be handled underwater? I have my suit & gear, renting the BC/Reg/Weights. ANy help would be greatly appreciated.