西表島 IriomoteIriomote

Iriomote became a World Natural Heritage site in 2021. You can kayak the mangroves of the Urauchi and Nakama rivers; Pinaisara Falls drops about 55 m, the highest in Okinawa Prefecture, and is currently limited to 200 visitors a day on booked tours (as of October 2026). Accommodation is limited; rent a car or use dive-shop pickups.

The main season is June to October, and April, May and November are quieter alternatives. Summer water is 27-29°C and the north coast around Uehara is calm; July to October is typhoon season, so keep spare days. During the winter northeast monsoon, fast boats to Uehara port in the north are often cancelled and run to Ohara port in the south instead, and diving moves to sheltered southern sites.

• Manta ray
• Turtles (nesting on Kuroshima beaches in summer)
• Coral spawning (around the May full moon)
• Jacks
• Reef fish
• Macro life

Mostly boat diving. The Yonara Channel has current and is intermediate; local shops report mantas there almost all year. Sekisei Lagoon is shallow and calm, and in many places snorkelers already see fields of branching and table coral. Nakanoganjin Island faces the open ocean with strong swell and current, suits experienced divers only, and is visited only in good conditions.

Yonara Channel

Between Iriomote and Kohama; mantas almost all year; intermediate.

Sekisei Lagoon

One of Japan's largest coral reef areas; shallow and calm, good for beginners and snorkelers.

Barasu Island

White sandbar made of coral rubble; dense coral on nearby shallow reefs.

Hatoma Island

Known for clear water; turtles common on the shallow reefs.

Nakanoganjin Island

Isolated offshore island to the south; big fish, strong swell and current; advanced.

Fly from Hong Kong to Ishigaki (seasonal direct flights or via Naha), then take a fast boat from Ishigaki's outer-island terminal: about 45-50 minutes to Uehara port in the north or 40-45 minutes to Ohara port in the south. For Hatoma, change at Uehara for another 10-15 minutes.

1. The Yonara Channel and Nakanoganjin have strong current; stay with the guide and know how to deploy an SMB.
2. Boats are often cancelled in winter and around typhoons; do not book the boat back to Ishigaki and your flight home too close together.
3. The nearest hyperbaric unit is at Okinawa Prefectural Yaeyama Hospital on Ishigaki; serious cases may go on to the main island. Breathe oxygen first.
4. In the national park, do not touch coral or take star sand or coral rubble.
5. Do not shine lights at or approach nesting turtles; drive slowly on island roads to avoid hitting Iriomote cats.