Which countries are included in Region B alongside Japan?

Region B of the IALA Maritime Buoyage System includes countries that adopt the use of cardinal marks and other navigational aids that primarily follow the left-hand traffic rule. Japan is part of this region primarily due to its maritime practices aligning with those found in nearby East Asian countries.

North Korea and South Korea are also included because both countries operate under similar buoyage systems that accommodate the unique geographical and navigational requirements of the region. This alignment facilitates safe navigation and helps avoid confusion, especially for international maritime traffic.

Countries like Australia and New Zealand, Canada, and Mexico belong in Region A, where a different set of buoyage and navigational aid standards is employed, while the Philippines and Thailand, while close geographically, also fall under a different maritime practice that aligns more with Region A. Hence, the inclusion of North Korea and South Korea alongside Japan in Region B reflects their shared adherence to the principles defined by IALA for this particular maritime area.