Guam: The Pacific’s Best-Kept Scuba Secret

If you want warm water, big visibility, WWII wrecks that whisper history, and reef walls that roll away into cobalt blue, Guam checks every box. This 30-mile island in the western Pacific sits at a crossroads between Asia and Micronesia, but underwater it feels like its own world – uncrowded, dramatic and surprisingly varied. In this guide we’ll take you from the airport steps to the ocean’s edge, point out the must-dive sites (and why they matter), explain what to expect below the surface, and show why Guam deserves a place on every diver’s map.

The dives you can’t miss

The Blue Hole (Orote Peninsula) – Guam’s signature dive

A dramatic sinkhole that starts shallow, funnels down and vents into the open ocean, the Blue Hole is atmospheric and photogenic. Divers enter along a reef shelf at around 15–20 m, then peer out toward the drop where pelagics like tuna and occasional reef sharks cruise by. Experienced divers can follow the wall to deeper water for a real sense of scale. Visibility here often soars, making it one of Guam’s standout experiences.

SMS Cormoran & Tokai Maru – two historic wrecks, one epic photo op

Off Apra Harbor rest two wrecks from different world wars lying close enough that you can swim between them which is a rare opportunity. The SMS Cormoran (scuttled in WWI) and the Tokai Maru (WWII) are encrusted with life and offer both macro interest and haunting, larger structure for penetration-free exploration. These wrecks are deep; plan the dive according to your certification, and consider a guided boat that runs the site.

Piti Bomb Holes & Gun Beach — easy shore dives, big returns

For quick entries and reliable marine life, Piti Bomb Holes and Gun Beach are favorites. Both are accessible from shore and host abundant reef fish, turtles, rays and interesting coral gardens which are perfect for shore-entry training dives, photographers and less experienced buddies. Gun Beach, in particular, is often rated the island’s best shore dive due to its easy access and variety.

11-Mile Reef & offshore walls for pelagics and clear blue

If you want the thrill of open-ocean reefs with big fish and possible sharks, head out to deeper reef systems offshore. These sites can produce strong visibility (often 20–30 m or more) and encounters with larger pelagics, especially on drift or wall dives. Boat access is required, and operators typically plan around currents and swell for the best conditions.

Getting there & practicalities

Fly into GUM (Antonio B. Won Pat International)

Guam is served by regular flights from Japan, the Philippines, Hawaii and parts of the U.S. west coast and acts as a convenient hub between Asia and Micronesia. The island uses U.S. currency and the airport is minutes from Tumon Bay, the main tourist area. Plan flights early if arriving from multiple connections; seasonal schedules change, so check carriers and routes before booking.

When to go

Diving is year-round. The climate is tropical and water temps sit around the low- to high-80s °F (≈27–29 °C), so a light suit or rashguard is usually enough. The “dry” season (roughly January–May) tends to bring calmer seas and still-excellent visibility, but many divers enjoy equally good conditions outside those months. Expect currents on some sites; local operators will match sites to your skills and conditions on the day.

Certification & crewed support

Most Guam dive operators are PADI/SSI affiliated and run training from Discover Scuba to advanced courses. Wrecks like Tokai Maru/Cormoran are deep so check depth limits on your certification (and consider a guided deep wreck specialty or a nitrox plan for longer bottom time). Boat dives, shore dives and drift options are all available; reputable operators provide full rental gear, tanks, and local briefings.

What to expect below the surface

• Visibility & water temp: Typically excellent visibility (often 20–30+ m) and warm water year-round; lightweight exposure protection is fine.
• Currents: Some wall and outer reef sites have strong currents so drift experience helps. Local captains will advise where and when to go.
• Marine life: From reef fish, turtles and rays to schooling tuna and reef sharks offshore. Wrecks add nudibranchs, lionfish and macro life thriving in structure.
• Depth ranges: Many signature sites have shallow-to-moderate options, but Guam also offers deep wrecks and wall drops. Check your training and plan accordingly.

Logistics, safety & local tips

• Book reputable operators. Look for local shops with good reviews and experienced captains as they know currents, seasonal patterns and safe entry/exit points.
• Wreck etiquette. WWII wrecks are both heritage sites and marine habitats. Avoid penetration unless properly trained and never remove artifacts.
• Gear & comfort. Bring a surface signaling device, reef-safe sunscreen, and a 1 mm-3 mm suit or long sleeve for sun protection and mild thermal comfort. Many operators rent gear, but if you shoot photos bring your own rig.
• Health & regs. Guam is U.S. territory so medical facilities and emergency evacuation options are good for the region. Travel insurance and dive-specific coverage are still recommended.

Why divers should choose Guam

Guam delivers a rare combo: accessible international flights, consistently warm water and visibility, dramatic WWII wrecks you can swim between, and a variety of shore-entry and boat dives that suit new and advanced divers alike. It’s a place where history meets healthy reefs and pelagic encounters and where the dive boats rarely feel overcrowded. For photographers, wreck hunters and pelagic chasers, Guam offers a compact but full Pacific diving experience without the crowds or long transit days.

Quick planning checklist

• Fly to GUM (Antonio B. Won Pat Intl); arrange rental car or hotel transfer.
• Book dives & at least one wreck trip in advance.
• Bring light exposure protection and reef-safe sunblock; consider nitrox for deep wreck days.
• Respect wreck heritage and local marine-park rules.

Guam’s underwater world rewards divers who come with curiosity and a sense of adventure. Whether you’re dropping into the Blue Hole, drifting past a reef wall, or drifting slowly over a century’s worth of seafaring history on the Cormoran and Tokai Maru, the island offers memorable dives that linger long after you climb aboard the boat. Pack your camera and your sense of wonder.