Ocean floating installations (1) are disposed on the ocean. The ocean floating installations (1) float on the ocean with the lower part of the ocean floating installations (1) being fixed to the seabed by mooring ropes (11). Each of the ocean floating installations (1) is connected at a connection part (5a) to a cable (3), which is a first cable. Each of the cables (3) is connected at a connection part (5b) to a cable (7), which is a second cable. In other words, the ocean floating installations (1) are connected to each other by the cables (3) and the cable (7). A connection is established with the cables (7) at the connection parts (5b) located on the seabed. In other words, the cables (7) are installed on the seabed.