小笠原群島 Ogasawara IslandsOgasawara Islands

Diving is based on Chichijima, with coral reef, rocks and several Second World War wrecks around the island. Hahajima is a further boat ride of about two hours and even quieter; the Mukojima group to the north is a long run and only visited in good weather. Besides scuba, the other main activity is dolphin snorkelling: the boat finds a pod and the guide lets you in only when the dolphins seem willing to stay. It is snorkelling, not diving.

The main season is June to October, with February to May and November also workable. Summer water is about 27-28°C and the sea is calm, the best time for diving and dolphins; July to October brings typhoons, and a rescheduled sailing can push back the whole trip. In winter (December to March) the water drops to about 19-20°C and north-easterly wind raises the offshore swell, but humpback whales arrive from about late November and are most numerous from February to April. Choose February to April for whales, July to September for diving and dolphins.

• Indo-Pacific bottlenose and spinner dolphins (all year, snorkelling)
• Humpback whale (from about late November, most from February to April; seen from boats)
• Green turtle (all year; an important nesting site in Japan, beach nesting in summer)
• Sand tiger shark
• Reef sharks
• Jacks
• Reef fish, including endemic species

Mostly boat diving in the channel between Chichijima and Anijima and around Minamijima, with short rides; beginner to intermediate. On days with current you may see reef sharks, jacks and sand tiger sharks. The Hinko Maru wreck at Sakaiura is so shallow that part of the hull is above water and can be reached snorkelling from the beach, an entry-level wreck. Hahajima is quiet, and the Mukojima group is further and weather-dependent, intermediate and above. Because medical evacuation takes so long, dive more conservatively than usual.

Around Chichijima

Boat dives, beginner to intermediate; coral, reef sharks and wrecks with short rides.

Hinko Maru, Sakaiura

Cargo ship abandoned after a 1944 air raid, partly above water; shore or boat dive, also reachable snorkelling from the beach.

Chichijima-Anijima channel

Boat dives with current; reef sharks, jacks and a chance of sand tiger sharks.

Around Minamijima

Boat dive or snorkel, intermediate; topography, dolphins and turtles.

Hahajima

About two hours by boat from Chichijima; few divers, intermediate boat dives.

Mukojima group

To the north; long ride, needs good weather, intermediate and above, chance of big fish.

Dolphin snorkelling off Chichijima

Indo-Pacific bottlenose or spinner dolphins all year; the guide decides when to get in.

Fly Hong Kong to Tokyo, then take the Ogasawara Maru from Takeshiba pier to Futami port on Chichijima, about 24 hours each way. It is the only ship on the route, usually running a six-day cycle of two nights on board and three nights on the island; in high season extra sailings or schedule changes are possible, and a replacement ship runs during the annual dry-dock in May. Hahajima is a further boat ride of about two hours from Chichijima. Allow at least a week.

1. There is no airport and no hyperbaric chamber. Emergencies are flown by Self-Defense Force flying boat or helicopter via Iwo To to the mainland, on average about 10.5 hours from call to hospital. Dive conservatively: no decompression dives, a conservative computer setting, longer safety stops, and dive insurance that covers medical evacuation.
2. You return by ship, not plane, but the flight home from Tokyo still counts for flying after diving; divers usually skip diving on the day the ship leaves.
3. From July to October typhoons can reschedule the ship and delay the whole trip; keep spare days.
4. The islands are both a World Heritage site and a national park with voluntary tourism rules. Follow the crew's instructions when snorkelling with dolphins or watching whales; do not touch or chase. Humpback whales have approach-distance limits and getting in the water is not a free choice.
5. Accommodation is mainly guesthouses and small inns with limited rooms; book early for summer holidays, New Year and Golden Week.