Guam Dolphin Watching Cruise and Underwater Observatory

Agat Marina and the dolphin watching cruise

The cruise leaves from Agat Marina on the west coast of Guam, south of the island's main harbour. From here the boat heads into deep blue water along the coast, where the sea floor drops away quickly and pods of dolphins come to rest and feed. A Guam dolphin cruise is one of the most popular morning activities on the island, and this one keeps the time on the water to about fifty to sixty minutes, depending on where the dolphins are that day.

As you cruise, the guide watches for fins and splashes and tells you about the marine life around the island. You also enjoy wide views of the green coastline and the hills of southern Guam, and you may see flying fish skimming above the waves. A fruit soft drink is served on board. Dolphins are wild animals, so sightings are very likely but not guaranteed; if none appear on your cruise, you receive a small gift.

Spinner and bottlenose dolphins of Guam

The dolphins most often seen off Guam are spinner dolphins, slender animals that travel in lively groups and are famous for leaping out of the water and spinning in the air. Bottlenose dolphins, larger and calmer, are also found in these waters. Both live here all year, which is why dolphin watching in Guam works in every season and why morning departures are popular, when the sea is usually calmer.

The boat watches the dolphins from a respectful distance and lets them come closer if they wish, without chasing them. Keep your camera ready, as the best moments often happen in a second, with a group surfacing beside the bow or a spinner flying out of the water. Children usually love this part of the tour most. People who are prone to seasickness should take precautions, as the open sea can have some swell even on fine days.

The underwater observatory in Piti

After the cruise the tour continues to the underwater observatory on the coast of Piti, a round tower that stands in the sea at the end of a long pier over the reef. You walk out above the turquoise reef flat and then go down a staircase into a viewing room below the surface, where large windows look straight out onto the reef. It is a dry, easy way to see what snorkellers see, and it suits all ages.

Through the windows you watch tropical fish of many kinds, from parrotfish and butterflyfish to schools of small reef fish, moving among corals just outside the glass. The observatory and its visitor centre say more than two hundred fish species can be seen in these waters. You spend about forty minutes here, with a guide explaining what you see. People often ask whether the underwater observatory in Guam is worth visiting: for families and non-swimmers it is one of the highlights of the island.

Piti marine preserve and the west coast

The observatory sits inside the Piti Bomb Holes Marine Preserve, a protected stretch of reef flat on the west coast of Guam. Its name comes from the deep blue holes scattered across the shallow reef, which look like bomb craters from above but are in fact natural sinkholes in the reef. Fishing is restricted here, so the fish are abundant and the reef is a favourite with snorkellers and divers.

The preserve lies along the main coastal road between the hotel district of Tumon and the south of the island, close to the capital Hagatna, also called Agana. With the default option our driver collects you from your hotel in Tumon or Agana, so you do not need to think about how to get to Piti or to Agat Marina. Bring a light jacket for the air-conditioned bus, and plan the rest of your day around a return in the early afternoon.

Lunch buffet and practical tips

The default option ends with a lunch buffet that offers a wide choice of dishes, including vegetarian options, so everyone can find something to suit their diet. It is a relaxed way to finish the morning after the sea air before our driver takes you back to your hotel. Options without lunch are also available if you prefer to eat in Tumon later.

The tour runs in sessions in the morning, and the session you join depends on availability on the day; we confirm your check-in time after booking. A minimum number of paying adults is needed for each departure. Arrive five to ten minutes before check-in if you meet at the visitor centre. Wheelchair users can join the tour, and Wi-Fi is available at the visitor centre and the observatory. The best time to book is a few days ahead, especially in the busy holiday seasons.