My first thought was "how the [ at ] #$%^ can someone be so lucky as to be forced to go to Greece for a week of "work"????? I was there 30 years ago and was not a diver then,,,,, too bad for me. I did hit the many beaches and several islands and I would think I would be happy diving anywhere there is a dive shop. Ususally,,,, if there is a dive shop around then that means there is good diving around there too.
I certainly wish you a good time at "work". ;)