Guam

February through May is the sweet spot for calmer seas and lighter winds on the leeward west coast. The Blue Hole begins near 18 m and opens around 38 m, so you want low surge for the wall drift. If trades build or there are swell advisories, operators may switch to Apra Harbor reefs where conditions remain manageable. Always carry an SMB for open water pickups outside the harbor.

Book a guided charter from Cabras Marina with an operator experienced in Apra Harbor wrecks. The sites are deep recreational dives, so Advanced Open Water and recent deep experience are recommended. Expect currents on ascent and boat traffic. Use nitrox if available and stay within no decompression limits. A reel and SMB help for a controlled drift pickup after exploration around the wreck pair.

Marine preserves such as Piti Bomb Holes and Tumon Bay prohibit taking or disturbing marine life and ban anchoring on coral. Enter over sand, keep fins off the bottom, and never touch or collect coral, shells, or live rock. Use reef safe sunscreen and mooring buoys where provided. Rangers actively patrol and boundaries are marked on shore signs.

Requirements match U.S. destinations. All arrivals must complete the Guam Electronic Declaration Form, one per family, up to 72 hours before landing. Many travelers from Australia, Japan, Korea, and other listed places can visit visa free for up to 45 days under the Guam CNMI Visa Waiver using the new ETA. U.S. travelers need acceptable REAL ID compliant identification for domestic flights starting May 7, 2025.

Water sits near 27°C to 29°C. Most divers are comfortable in a 3 mm suit or a skin with a thermal top. Booties help for occasional shore entries. Bring an SMB and whistle for blue water pickups, a compact torch for caverns and wreck nooks, and a lightweight rain shell for boat rides during rainy months. Pack reef safe sunscreen for preserves.

The Guam Regional Transit Authority runs limited bus routes roughly from early morning to early evening Monday to Saturday, with no service on Sundays. Routes do not consistently reach marinas on dive schedules. Most divers rent a car, arrange hotel shuttles, use taxis, or book Stroll Guam ride hailing to reach Cabras Marina on time for morning departures.

Box jellyfish pulses and Indo Pacific man o' war reports occur in some summer windows, especially around July. Wear a rashguard, avoid contact with any washed up tentacles, and follow local advisories. If stung, exit the water, rinse with vinegar or seawater, and seek medical assessment if symptoms escalate. Operators will monitor conditions and advise safe alternatives.

Beginners will enjoy Apra Harbor sites like Gab Gab II and Western Shoals for moderate depth and abundant fish. Advanced divers target Blue Hole, Sharks Pit, and the Tokai Maru plus SMS Cormoran wreck pair. Conditions outside the harbor can include current and surge, so plan with your operator and be honest about recent experience to match sites to skills.

Yes. Guam Regional Medical City operates hyperbaric oxygen therapy services and a 24 hour emergency department. Guam Memorial Hospital in Tamuning also runs an emergency department. Dial 911 for emergencies and contact DAN at +1 919 684 9111 for diving medical support. Charter captains coordinate with the U.S. Coast Guard for on water incidents.