The IDR shares mechanical design and electrical components (SD card, USB interface, battery, etc.) with the Enduro APT Recorder, but has no sensors. Specialized firmware allows the IDR to transmit in response to individual or group commands, yet ignore commands that would stop recording. The IDR is easily hand held and installs concentrically on the mooring wire in seconds using a cordless driver. Its uniquely small tapered shape reduces dynamic stress on the mooring and fends off fishing lines or debris that might otherwise snag the instrument.