The Marine Park is highlighted by its largest sinkhole called "Piti Bomb-hole", or collapsed area of the reef, that is filled with fine, white sand and enclosed by the beautiful coral garden that encircles the underwater observatory. Known to be a paradise of marine life, it is home to various species of colorful tropical fish and coral. You will be fitted for equipment and given a thorough safety and snorkeling briefing at the observatory's upper before heading down into the sea.
Snorkeling one of Guam's top marine attractions was never so easy and fascinating. Your trip to the stunning reefs and colorful fish of Piti Bay begins with a walk on the water! You will venture out over Piti Bay along our extensive boardwalk. This brings the colors and waters of the bay into close view. This is a designated marine preserve and we call it the Fish Eye Marine Park.
We will begin snorkeling in Guam's warm waters by practicing around the designated area under the supervision of our snorkeling guides. Once you are comfortable with the equipment, the fun begins. At all times, guides escort you around the coral garden and show you the marine life of fish and corals. You'll experience the excitement of being surrounded by masses of tropical fish, sea the rich coral growth and even look for tiny crabs and shrimp. You will even feed the fish on your tour and sea anemones and "Nemo" clownfish.
This snorkeling area around "Bomb-hole" is one of the most diverse areas in Micronesia with places for young fish to grow, cleaning areas where small fish preen larger fish and over 200 fish species living in this fantasyland. After your snorkel, you will shower and be fed a delicious lunch buffet. Eat, drink and relax as you look out to the lagoon and tropical jungle garden.
The information is from http://fisheyeguam.com/e_activities_snorkeling.htm