Galapagos is full of marine life. While you will have to go diving to see some of it, there is lots to see from the land and from snorkeling on the surface.
Galapagos Marine Life Gallery
Galapagos Marine Life Photos
For higher resolution, click image.
Blue Striped Grunt Fish
Whale Shark in the Galapagos
Galapagos Sea Lion (see more sea lions)