I dive Tres Palmas pretty frequently, and I typically shore dive this site at the second reef. Most folks jump in the water and dive the area nearshore, but you're missing a lot of the bigger fish that await you just a short kick further.
In about 15 minutes, you can kick out to the second reef of Tres Palmas, at a depth of about 40 ft max, and see schools of parrotfish, snapper and many transient species like jacks. The water clarity is typically a bit better out here too, and many turtles are spotted swimming over the shallow areas of this reef.
You can ask Rincon Diving & Snorkeling to take you here!