Ocean wave information is indispensable for a coastal activity and service of ship to be carried out safely and economically. A low-cost wave height and direction sensor was developed by Japan Aerospace Exploration Agency and Japan Weather Association. The purpose of this study is to examine observation accuracy of wave height, period, and direction on the light buoy of Japan Coast Guard. Then, we installed a low-cost wave height and direction sensor on the light buoy and observed ocean wave in the sea. And, we compared data observed by light buoy with data observed by NOWPHAS (Nationwide Ocean Wave information network for Port and HArbourS). Our results show that observation accuracy on the light buoy is high.
