Tsushima City is located on an island located between mainland Kyushu and the Korean Peninsula, serving as a border island. The surrounding waters of Tsushima are where the Tsushima Warm Current and coastal waters of the continent intersect, creating favorable fishing grounds due to the undulating seafloor topography. The diverse rias coastline is suitable for marine aquaculture. Osaki Fishing Port continues to expand as one of the premier aquaculture base ports on the island. This report introduces the synergistic effects of breakwater development aimed at securing calm areas within the port.