manual control must be executed slowly because of large inertias. Computer-aided control can make use of predictor displays to anticipate the effects of control actions before they are imposed, thus adding lead stabilization.
Two widely publicized deep ocean-teleoperations were used in the recovery of the accidentally air-dropped hydrogen bomb off the Polomares Islands in 1967 and the discovery and exploration of the ship Titanic. In the former, the Navy vehicle CURV (cable-operated underwater remote vehicle), equipped with a pressure-sealed camera, lights, and manipulator, was dragged until the parachute attached to the bomb could be found and grasped. In the second case, the Woods Hole Oceanographic Institution submersible vehicle Argo was passively towed at the end of a several-mile-long cable, and its cameras, lights, and powerful sonar were used to discover the Titanic (Whitcomb and Yoerger, 1993). The small ROV (remotely operated vehicle) Jason then explored inside the Titanic at the end of its power and signal umbilical. Deep-ocean teleoperators have also found a number of other sunken ships, historic artifacts, and buried treasure, as well as discovering the existence of hydrothermal vents deep on the ocean floor.
Deep-ocean vehicles, sensors, and manipulators have been used to survey the ocean bottom topographically, geologically, and biologically. It has been estimated by some biologists that more than 90 percent (volumetrically) of the earth's ecosphere has yet to be explored—namely, the oceans below the surface—and it is already clear that the oceans are full of creatures at all depths. Teleoperators appear to be an ideal way to perform this exploration.
A more commercial application of teleoperation in ocean environments has been in the area of off-shore oil exploration. Many petroleum wellhead preparations have been performed by teleoperators. Still other operations that might have been done by teleoperation have been neglected, such as inspection and repair of the legs of oil platforms (some of which have broken up in heavy seas because their welds cracked) and inspection of outflow pipe lines (some of which have burst for similar reasons). Many associated underwater robotic technologies still need much development, such as cleaning, inspection of welds, and rewelding.
The usefulness of teleoperation in a particular hazardous domain may not be at issue, but its costs may well be. In many cases, it is simply more