Tumon Bay is a 1.5-mile long sandy beach in Guam featuring a large lagoon and a reef drop-off. The site is suitable for beginners in the shallow lagoon, while the drop-off provides more depth for experienced snorkelers and divers. Depths range from 1 to 30 metres, with an average of 1 metre in the shallows. Visibility varies between 5 and 30 metres. Access is via the shore, and the site offers facilities including equipment rental, parking, toilets, and showers. Be aware of potential hazards such as boat traffic, jellyfish, rip currents, sea urchins, sharp coral, and strong currents. Night diving is available at this location.

Gun Beach is located at the northern end of Tumon Bay, Guam, offering a diverse underwater environment that transitions from shallow, protected coral areas to deeper reef sections. Divers and snorkellers can access the site from the shore, with the reef located approximately 50 metres out. Depths range from 1 to 40 metres, with an average of 10 metres. Conditions include moderate currents and visibility between 18 and 23 metres. Water temperatures remain between 28 and 30 degrees Celsius, though some find the water cooler than other island locations. Facilities at the beach include parking, toilets, and showers. Hazards include sea urchins, sharp coral, surf, and strong currents.

Faifai Beach in Tumon Bay offers accessible shore-entry snorkelling along a narrow reef. The site is suitable for beginners, with depths ranging from 1 to 5 metres. Snorkellers can expect a typical session duration of 60 minutes in water temperatures between 28C and 30C. Conditions are generally mild, though visitors should be aware of potential hazards including surf, rip currents, jellyfish, lionfish, stonefish, and sea urchins, as well as sharp coral. Facilities available at the beach include parking, toilets, showers, and changing rooms.

Piti Bomb Hole in Apra Harbor is a shallow reef site accessible via a shore entry. Located 69 metres from the shore, the site features an average depth of 8 metres, with a range between 5 and 11 metres. Conditions are generally mild with visibility ranging from 10 to 30 metres. The site is suitable for beginners and those seeking a refresher dive. Divers can observe a variety of marine life, including common wrasses and Pacific doublesaddle butterflyfish. Less frequently encountered species include emperor angelfish, Napoleon wrasse, titan triggerfish, snowflake moray, longhorn cowfish, Indian lionfish, day octopus, regal angelfish, Brummer's moray, rock cod, masked bannerfish, and blackback anemonefish.

Fish Eye in Apra Harbor features a combination of natural reef and artificial structures accessible via a shore entry. The site is suitable for beginners, with depths ranging from 1 to 12 metres and an average depth of 8 metres. Divers and snorkellers experience mild currents and visibility between 6 and 10 metres. Water temperatures remain consistent between 28 and 30 degrees Celsius throughout the year. Facilities at the location include parking, toilets, and a cafe. Due to active boat traffic in the harbour, divers should maintain high situational awareness and deploy a surface marker buoy during ascents.

Piti Canal in Apra Harbor, Guam, offers a shallow dive experience across reef, seagrass, and artificial reef habitats. With an average depth of 6 metres, this shore-entry site is suitable for beginners, though divers should be prepared for strong currents and surf. Visibility varies significantly, ranging from 9 to 45 metres. Marine life recorded here includes wrasses, pufferfish, and yellow tang, alongside less common sightings such as Spanish Dancer, spotfin lionfish, day octopus, and giant moray. The site is also accessible for night diving, with typical dives lasting around 60 minutes.

Amphitheater in Apra Harbor, Guam, is a reef and wall site defined by its natural curvature and significant drop-off. Divers can explore depths ranging from 9 to 40 metres. The site features deep water corals along the wall structure. Visibility is generally good, typically ranging from 18 to 61 metres. Access is by boat only, and the site is suited for advanced divers due to the potential for moderate currents, deep water, and surf conditions. Species recorded around this area include various wrasses, pufferfish, butterflyfish, lionfish, and trevally, though these are not confirmed sightings at this specific location.

Fuel Pier in Apra Harbor, Guam, is an artificial reef and wreck site accessible only by boat. Divers typically explore the structure at depths ranging from 14 to 27 metres, with an average depth of 25 metres. The site presents challenging conditions, including low visibility between 1 and 3 metres, potential entanglement hazards, and active boat traffic. Due to the overhead environment and limited visibility, this site is suited for intermediate divers. Night diving is permitted. Species recorded around this area include wrasses, triggerfish, angelfish, and moray eels, though these are not confirmed sightings at the pier itself.