You must check out this operator

http://www.sunrisediverscozumel.com/index.html

Experience and diversity is this operators strong points.
Safety is a given and obvious from the time you say hello to the time
you say see ya mañana.

Customized trips.. Cozumel, Playa, and right now, whale shark watching.
They are reporting 15-20 sharks a trip...

Check them out. They are located just south of Fiesta Americana and
will pick up at almost any hotel.. They even have a twilight dive...
Yawn... 5am pickup.. But your back in plenty of time to catch the 9am
boat :-).....

Enjoy,

We were just talking about the Whale Shark trips to Mexico (Holbox Island) today! Check out: http://www.holboxisland.com/tours/whale-shark/ We have not done this yet, but some friends did it and said it was great. They did not go with Sunrise Divers though, I do know that.