June, we just returned from AC and dove with Amigos del Mar. It's a fine shop that will cater to anybody's individual needs. We took our newly cert 13 yr old son and they were good with him. We have dive Turneffe atoll before and wanted to again so we took the day trip to south Turneffe and dove the Elbow, Billy Bob's and the Syanora wreck...alll EXCELLENT dives with eels, eagle rays and turtles and tons of marine life. If you are an experienced diver they will not bug you about depth and time.
The local diving, especially Tackle Box and San Pedro Canyons, are great sites with swim thrus and canyons. Of course, the Hol Chan area is good for a close-in night dive.