Ditto Ryan's comments. Rey is a great DM. He also goes to the better dive sites (Tres Hermanas and Salmedina) that the other local dive ops only visit when the seas are totally flat from September through November. Golden Frog's rates are better, too.
I gave up trying to book with the dive operator on Contadora. Plus, one of my Panamanian friends who dove there said the diving is not good off Contadora. She saw very little marine life and no coral.
Isla Coiba is for experienced divers. It's best done as a multi-day dive trip, because it's a 90 minute boat ride from Santa Catalina to Coiba. So, you have to be staying overnight near the island to get to the better dive sites. Santa Catalina is also a 7 1/2 hour drive from Panama City. The conditions are challenging -- deep dives, strong currents, visibility can go from 45 feet to 4 feet in moments. There is a thermocline with a temperature change from mid/low 80s to low 70s/upper 60s. Buoyancy control is a must because safety stops will be in blue water. In spite of all that, the marine life is amazing! Lots of sharks, huge schools of jacks and barracuda, neon frogfish, huge morays and many species of Pacific reef fish. At different times during the year, there are humpback whales calving, whale sharks visiting and mobula rays.