Written by DiveJourney. Built from public sources and local operator knowledge. Last updated Dec 7, 2025.

• DiveJourney Destinations (Japan discovery) - Used to identify DiveJourney destinations listed for Japan (currently includes Okinawa).
• DiveJourney: Okinawa destination - Internal reference for Okinawa planning anchors and regional context.
• DiveJourney: Yonaguni Monument/ Underwater Ruins - Internal dive spot anchor for Yonaguni seasonal planning.
• DiveJourney: Osaki Hanagoi Reef - Internal dive spot anchor for Ishigaki and Yaeyama reefs.
• DiveJourney: Yaene (Hachijojima) - Internal dive spot anchor for the Izu Islands (Tokyo-accessible diving).
• DiveJourney: Rausu (Shiretoko) - Internal dive spot anchor for drift ice season planning.
• DiveJourney: Sea Of Okhotsk - Internal dive spot anchor for cold-water and ice diving context.
• DiveJourney: Dobuiso (Ogasawara) - Internal dive spot anchor for Ogasawara Islands planning.
• Japan Meteorological Agency: Tables of climatological normals (1991-2020) - Monthly climate normals used for air temperature seasonality framing.
• JMA Ocean: Sea surface temperature around Japan (area averages) - Source for seasonal sea surface temperature normals by region.
• JMA SST data: Sakishima area (seasonal normals) - Seasonal sea temperature normals used for southern Okinawa context.
• JMA SST data: South of Kanto (seasonal normals) - Seasonal sea temperature normals used for Tokyo-area and Izu context.
• JMA SST data: Sea off Shikoku and Tokai (seasonal normals) - Seasonal sea temperature normals used for warm-temperate Pacific context.
• JMA SST data: Sea off Sanriku (seasonal normals) - Seasonal sea temperature normals used for Tohoku temperate diving context.
• JMA SST data: Sea off Kushiro (seasonal normals) - Seasonal sea temperature normals used for eastern Hokkaido context.
• Ministry of Foreign Affairs of Japan: Visa exemption (short-term stay) - Official visa exemption reference for entry planning.
• Visit Japan Web (Digital Agency services landing page) - Official arrival procedures platform reference (immigration and customs workflows).
• National Tax Agency: International Tourist Tax leaflet - Official outline and rate for the International Tourist Tax (departure tax).
• National Parks of Japan official site - Official park system overview and park pages for island regions relevant to diving and snorkeling.
• National Parks of Japan: Park rules, safety, and disaster information - High-level official guidance on coral protection, wildlife safety, and park behavior.