I am not sure about diving Taboga, not much to see. Small and lovely Island about 45 min. ferry ride from Panama City. The last time I was there 3 years ago. The small patches of reef are almost dead and the rest are rocks. Visibility depends on the time of the year and weather. However if you plan spear fishing you might get fun.
I would recommend you to go to Bocas Del Toro. You will enjoy diving there. Town has 3 or 4 dive shops that will pair you up with someone. Hope this helps a bit.