MIL-U-18033F, MILITARY SPECIFICATION: UNDERWATER LOG EQUIPMENT, ELECTROMAGNETIC TYPE (20 NOV 1962)

MIL-U-18033F, MILITARY SPECIFICATION: UNDERWATER LOG EQUIPMENT, ELECTROMAGNETIC TYPE (20 NOV 1962)., This specification covers electromagnetic underwater log equipment, for use on Naval ships. This equipment provides a means of measuring, indicating, and transmitting ships' speed and distance relative to the water.