Abstract: I provide a combination land/bay cable capable for simultaneous use on land and in water-covered areas. When the cable section is placed in a water-covered area suitable for hydrophone use, a polarized plug containing an impedance matching transformer is detachably connected to a polarized socket. The transformer connects the hydrophones to a transmission line. If the cable is to be used on land, the transformer is unplugged deactivating the hydrophones and at least one geophone having a substantially identical plug is inserted in the socket. The plug connects the geophone to the transmission line and leaves the hydrophones inactive.