The expendable wire link (XWL) is a new electrical transmission device that permits short-term hard-wire electrical connection to an instrument package being deployed from ship or aircraft. This hard-wire "link" is a 0.008-in-diam cable with a weight of less than 4 g/100 ft. With an electrical connection device of this type, closed-circuit telemetry, voice communications, measurement, and sensing devices may be deployed simply and reliably from a variety of moving vessels without the need for associated complex radio or sonar transmitting and receiving equipment. Expendable wire links are operational. Links ten mi in length have been deployed for data transmission, reducing substantially the complexity of interfacing peripheral equipment. The telemetering package remains directly connected to instrumentation aboard the vessel. It is unaffected by the surrounding environment and is independent of the vessel's speed or maneuvering. Presently available are two- and three-conductor, expendable wire links of 0.008- and 0.010-in diam, respectively. Units are fabricated to customer specifications in quantities of from 12 to 10 000.