The purpose of this study is to develop a high performance propulsive mechanism with high efficiency at high sailing speed by using a mechanism of rotary reciprocating wing motion based on the two-dimensional Weis-Fogh model. The sailing tests by both towing the model ship and its self-propulsion were carried out. In the towing test, the thrust of the model ship, the drag acting on the wing, and the wing opening angle in motion were measured for various parameters such as the wing moving speed and the sailing speed of the model ship. On the other hand, in the self-propulsion test the sailing speed of the model ship was measured for various frequency of wing reciprocating motion. The following results were obtained. The change of the wing opening angle in the mechanism of rotary reciprocating wing motion is obviously different from that of the wing opening angle in the mechanism of linear reciprocating wing motion. It was confirmed that the former is effective for the speeding up of the wing motion in comparison with the latter.