INFLUENCE OF INSTALATION JENGTH OF LOW-REFLECTIVE BREAKWATERS ON THE HARBOR ENTRANCE TRANQUILITY

For safer passage of comparatively small ships, such as fish boats, through a harborentrance, low-reflective typebreakwaters are usually adopted at the harbor entrance. However, construction cost of thelow-reflective typebreakwater is comparatively high as compared to a conventional vertical breakwater. In orderto know the minimumand necessary length of the low-reflective type breakwaters at the harbor entrance, tranquility in the sea area near andat the entrance is examined from both the experimental and theoretical points of view. Adouble-walled breakwatersupported by piles was used as a low-reflective type breakwater. Changing the installationlength of a double-walledbreakwater from the harbor mouth, wave height distributions around the harbor entrance wereprecisely examined.