The paper summarizes the design concept and outline of a buoy system for monitoring a coastal sea state. Miniaturization of the buoy was achieved by submerging it in severe sea conditions. The configurations and tensions of the mooring lines in disturbances were calculated, and it was confirmed that the design concept can be realized.
If the sea state during one year is measured by a buoy system in-stalled in a coastal fishery and the information is distributed to fisher-men in real time, judgment of efficient fishing can be possible and the rising waste of high-cost fuel on fishing boat can be prevented. The installation and maintenance of such a system by fishermen is desirable, and considering the work done by small fishing boats, miniaturization of the buoy is essential. However, the state of the sea at the offing in Tottori where installation is planned is severe in the winter season, the surface buoy which should not submerge requires large surplus buoyancy, and makes the size large. Therefore, miniaturization of the buoy was attained by allowing submersion in a sea condition in which fishing is usually impossible. The threshold conditions were decided by the experiences of fishermen. This paper summarizes the design concept and outline of the buoy system for monitoring the coastal sea state and shows the calculated results of the configurations under disturbances. The simulated results verified that the design concept can be realized.
The installation position of the buoy system and the mooring conditions are shown in Fig.1 and Fig.2, respectively. We are planning ocean observation for about three months even in the winter season. However, the state of the sea at the offing in Tottori shown in Fig.1 is severe in winter, and a traditional surface buoy system which does not allow submersion requires large surplus buoyancy and the size is very large as shown in the last part of this paper.
