The information of ship waves generated by a small boat is very important to prevent damage of the floating marine structure such as the cage for fishing aqua-culture. This paper deals with the measurements of ship waves generated by three kinds of actual small boats, a displacement boat, a high-speed boat and a planing boat. The main purpose of this study is to investigate the fundamental characteristics of waves generated by a small boat passing near the marine structures. The measurements of ship waves are carried out in the cases of varying distance from the sailing line with constant ship speed and varying ship speed with constant distance from the sailing line. The measured ship waves are compared with ones calculated by two kinds of simplified estimation methods and the evaluations of these methods are also investigated. As results, the both calculated results show relatively good agreement with the measured ones of a displacement boat and a high-speed boat, but have discrepancy with ones of a planing boat.
