Scientists from academies and industries in the maritime countries of the US, Britain, Norway, Russia, Italy, and Canada document the transition from the dream in the 1980s to the reality of robotic vehicles operating under the ocean for scientific research, defense, surveying, and industry. They emphasize civilian applications, though one study describes defense applications to recognize that the military is behind much of the development. Among other topics are power sources, advanced materials and their influence on structural design, propulsion systems, detailed seabed surveys, cargo carrying vehicles, and the legal regime.