I had a week cruise round the Galapagos Islands with Steppes Travel, http://www.steppestravel.com on the Cormorant, a 33m luxury catamaran with a local guide. We were lucky to snorkel with Galapagos Fur Seals (actually Sealions), which are very playful. They came right up to us and were continually racing round us underwater. When we left they followed our boat calling, as if they still wanted us to play with them. These were filmed off Fernandina Island. Unfortunately, the water clarity was not good as there had been a storm the previous night.
The Green Turtles were also very friendly, coming right up to us without fear. The currents were quite strong and we and they were thrown around a lot while filming. I have never been so close to a Green Turtle as in the Galapagos.
There were a few Parrotfish, but again the water clarity was poor.