The aviation and nuclear reactor industries, with a greater experience of simulator technology and its training value, use simulators for both training and licensing. The military (e.g. Navy) and other government agencies (e.g. National Aeronautics and Space Administration) have extensively used simulators for training and qualification. It has been suggested (Schumacker, Madsen and Nicastro, 1972; IMCO Standards of Training and Watchkeeping Convention of 1978, Resolution 17) that simulators could be used for proficiency demonstration on the part of mariners. The US Port and Tanker Safety Act of 1978 requires standards for licence qualifications by use of simulators.