A sensor cable for surveying. The sensor cable has a housing, which includes one of more electrodes and a conductive gel surrounding the one or more electrodes. The conductive gel is configured to conduct electrical current to the one or more electrodes and keep the one or more electrodes moist. The housing may also have a membrane surrounding the conductive gel, wherein the membrane is configured to hold the conductive gel in contact with the one or more electrodes and permit electric current to flow between a surrounding medium and the conductive gel.