Assessment of any significant effects on the local marine environment when considering the installation of a marine renewable energy device is of the utmost importance. In particular, the effect of such device on fish is concerned by local fishermen. To confirm variation of fish before and after installing the device of marine renewable energy, we investigated effective monitoring system using an underwater fish-eye camera. In this paper, visibility of the fish-eye camera was tested off Kamaishi city, Iwate prefecture, Japan, which is a test site of marine renewable energy in Japan. Device of wave power generation is planning to install at this site in the future. We confirmed the visibility of the fish-eye camera using a fish-shaped target by changing the distance between the target and camera. The water depth and photon were simultaneously measured. From the result, the horizontal visibility was discussed, and then we made a plan to observe around wave power generator using this fish-eye camera.