 When communications became difficult because of atmospheric conditions, the DAMP ship shifted to carrier wave (CW) transmission using standard Morse Code.In addition, because the ship could be out to sea for extended periods, such as a month or so, the DAMP ship carried an amateur radio room and equipment, which technical personnel could use to communicate with their families back home in the States via short wave radio.For local area communicating – for example, when in the Ascension Island area in the Atlantic or the Johnston Island area in the Pacific – the DAMP vessel had the capability of transmitting and receiving USB voice and LSB radioteletype to/from such island locations.