Arriving in Japan
This website provides most of the information you need for clearing in to Japan. Most important, you need to submit a Pre-Arrival Procedure Form more than 24 hours before arriving.Secruity Information of Ship – Japan Coast Guard
New pec is a Japan-specific charting software developed by the Japan Hydrographic Association. Although available as a laptop version or built in to various chartplotters, the best version is new pec smart, an iPad/iPhone app. It is great!! It has MUCH better detail than the Japan charts on CMAP, Navionics, and OpenCPN and comes with a LOT of very useful bells and whistles. Once you use it, you can't imagine cruising without it and will wonder why the same template has not been applied to overseas charts. Unfortunately, though, it's only available in Japanese and on the Apple Japan App Store, but a Japanese friend can probably help you figure it out or Konpira Consulting offers a start-up tutorial and ongoing support.
Charts and Other Information
Order them through the website of the Japan Hydrographic Association. In addition to all the small-scale charts for your cruising area (as a minimum), we especially recommend buying charts showing the location of fixed fishing nets ("set-net charts") and, for those planning on cruising in Japan for a long time, the S-Guides (books with chartlets for almost all Japanese ports; no longer available in book form but one can pay for a download and then print it out). Note, though, that if you have new pec (see above) then you don't need anything else, except whatever paper charts you desire for your own peace of mind.
Closed-Port Permit Application
Unless a port is specifically declared "Open," all of Japan is a "Closed Port" and foreign boats have to get advance permission for entering Closed Ports. Getting a Closed Port Permit, though, is now very easy and can be done before even arriving in Japan. The Permit covers the entire country and is valid for as long as the boat is in Japan.
Current Estimates (Offshore)
To see what's happening with the offshore currents (especially the strong Kuroshio Current), click on the box that says "海流図" on the top page of this website.
Current Calculations (Tidal)
Most (but not all) marinas and other facilities that have moorage for visiting boats are registered as Umi no Eki (Sea Stations), and information on them can be found at this website.Sea Stations – UMI no EKI
Seto Inland Sea
This website provides a lot of very useful information for those cruising the Seto Inland Sea.Setouchi Cruising Portal Site
Tide CalculationsThe tide prediction map (all Japan)
Monitoring the development and movement of a typhoon, and finding a safe place to sit out a typhoon, is an important part of cruising Japan safely.
The U.S. Navy's Joint Typhoon Warning Center generally provides the earliest and best forecasts.
The Japan Meteorological Agency has recently upgraded its forecast capabilities and so is now also an excellent source of information.
Typhoon 2000 shows the track forecasts for a typhoon from all the official weather agencies in northeast Asia.
Historic information on all the typhoons to have hit northeast Asia can be found at this website.
Far and away the best source for weather forecasts in Japan is GPV. It is, unfortunately, only available in Japanese, but a Japanese friend can probably help you figure it out or Konpira Consulting offers a start-up tutorial and ongoing support.Weather-GPV.info