in SW side, and 10 also with the Japan Sea through Kanmon Kaikyo in W extremity.
It is an ocean area, which is one of the most congested areas with marine traffic and there are a
number of traffics of huge vessels and the vessels towing or pushing long objects. There is a general
tendency to fog up and are the parts with shallow channels or with strong tidal streams.
Furthermore there are many fishing boats doing the seasonal or local unique fishing operation and
the passage conditions of vessels are rather tough