In Kochi Prefecture, surface type fish aggregating device for Katsuwonus pelamis and genus Thunnus is installed from December, 1984. In the Kochi ocean space, 15 sets of surface type fish aggregating device are fixed now. Among these, the apparatus which collects the situations of an oceanic condition is attached to three sets. Fishery operators utilize the information acquired from them, and judge whether it can sail out to fish. There are two kinds of surface type fish aggregating device, discus type and an ellipse type. Discus type is installed in the ocean space where oceanic conditions are severe. The Kochi prefecture fisheries experimental station investigates the effect on a fish catch every year. As a result, it turned out that the about 48 million yen effect per set is in one year. Proper arrangement is due to be considered in order to heighten an effect more from now on.