To reduce the equipment cost and to perform maritime observation in a narrow region by providing plural secondary stations under the control of primary stations and permitting the primary stations to execute communica tion relay between the secondary stations and a satellite.

An ocean communication system is constituted by the primary stations 1-3 of plural surface layer buoy-type observation stations arranged on the sea, water acoustic LAN 11-13 constituting the primary stations and the marine communication satellite 104 relaying data from the primary stations and transmitting them to a management station. The plural stations under the control of the primary stations constituting LAN 11-13 collect marine observation data and they are transmitted to the management station through the primary stations and the satellite 104. The cover ranges of respective LAN 11-13 are set to be one unit and LAN 11-13 cover the whole observation sea area. The system is constituted by satellite communication WAN where the satellite 104 is set to be the center and LAN 11-13 where the respective primary stations 1-3 are set to be the centers.