North of Guam International Airport in Tumon Bay, the snorkeling at Ypao Beach Park is very popular. The main snorkeling area in Tumon Bay Marine Park extends from the Reef Hotel to the Hilton Hotel. There are reef flats and patch coral formations with numerous species of hard corals including staghorn coral.
The best snorkeling in Tumon Bay is off Ypao Beach in the southern end of the bay. There are usually strong cross currents, so it is possible to drift dive across the reef parallel to shore and then walk back on the beach. Within the deep water here, you'll find staghorn coral with plentiful blue chromis, tangs, butterflyfish, pipefish, trunkfish and filefish. The waters range from 5 to 15 feet deep. Out deeper, you may encounter both stingrays and manta rays.
The best time of day for Ypao Beach Park snorkeling is slack high tide for the highest visibility.
To reach the Guam snorkeling by air, fly into the Antonio B. Won Pat International Airport (GUM) which is located in the middle of the island.
While the dry season is typically January to June, the best snorkeling on Guam is during the months of May through August. The highest water clarity can be found if there is an incoming tide during the morning. While snorkeling in Guam, keep an eye out for green sea turtles, hawksbill turtles and dozens of species of sharks. Overall, there are over 700 species of reef fish and over 300 species of coral on the fringing reefs. Most snorkelers stay within the fringing reef since there is usually a strong current just beyond the reef. There are a couple lesser well-known snorkeling dive sites off the east coast of Guam, which should only be attempted during the local summer months and then only with extreme care.
Overall, Ypao Beach Park is the 1st most popular snorkel dive spot of all 17 snorkeling dives in Guam.