A hydraulic system for a marine vessel incorporates a single hydraulic pump that can be driven by either first or second motive devices, such as an internal combustion engine or an electric motor. The receiving spacer layer includes a protection pad which is made of a soft foam material and has a first accommodation space to receive a first electronic device, and a bag fabric is connected to the first accommodation space to receive the first electronic device. The information for each of the plurality of personas includes a visibility level. The disk array device 1 performs remote-copying of the differential data 5 and difference management information to the disk array device 2 of a secondary site. The electronics assembly is operably associated with the wave guide probe for actuating the wave guide probe and producing an electrical output signal representative of a location of the fluid interface in the translucent tube.