the moon at Amami-Oshima Island and other relevant locations.
(8) Observation of Sea Ice and Waves
Ice floes gather along all the coastline of the Sea of Okhotsk and the eastern sea area of Hokkaido during the winter. They present great obstacles to ship navigation, commercial fishing, and other such maritime activities. In order to prevent maritime accidents caused by these ice floes, every year JMSA uses its patrol ships and aircraft to observe their dispersion and course. In addition, JMSA analyzes the sea area-oriented and seasonal characteristics of waves on the open seas and conducts wave observations in areas such as the seas south of Honshu, to contribute to the safety of navigation.
2. Providing Information to Ensure Safe Navigation
Along with publishing the Hydrographic charts and publications required to ensure safe navigation, JMSA issues Notices to Mariners related to marine traffic safety and ocean currents, to keep Hydrographic charts and publications as up-to-date as possible and to provide the information required for the safety of ship traffic.
(1) Hydrographic Charts and Publications, etc.
a. Charts
(i) Nautical Charts
The navigational charts essential to ensure safe navigation include harbor plans, coast charts, general charts of coast, sailing charts, charts for radio navigation, general charts, and electronic navigational charts (*Note 3). As of the end of FY 1995, 902 editions had been published
To update nautical charts, JMSA publishes new or revised charts, as well as Notices to Mariners with correction chartlets attached. In FY 1995, JMSA issued eight new and, 31 revised charts, and 270 correction chartlets. In particular, it annually publishes revised editions of nautical charts of the
*Note 3: Electronic Navigational Charts: Ships are becoming progressively larger and energy efficient as a result of the advancement of electronic technology. Amid the increasingly sophisticated use of electronics in navigational equipment, JMSA has been required to provide aid for safer and more efficient navigation for ships. It is for this reason that JMSA puts out electronic navigational charts based on an internationally uniform standard. Since FY 1992, it has been proceeding with digitization of nautical charts, development of software, and introduction of new equipment or improvement of existing equipment. In FY 1994, it put out the first electronic navigational chart (ENC) for the area covering from Tokyo Bay to Cape Ashizuri. In FY 1995, it issued ENCs for the areas covering from Kita-Kyushu to Ishigaki Island and to the Seto Inland Sea, and from Tsushima to the Sado Strait. During and after FY 1996, it will continue with the task of preparing digital nautical charts and publish them for coastal areas of Japan successively.
