The art of engineering

Sediment cloud stirred up by the operation of the sampling arm of the French submersible Soucoupe, one of a class of free-swimming vehicles designed for exploration of the ocean bottom. To overcome this obstruction to visual observation, short-range high-resolution sonar equipment may be standard equipment for any vehicle used for manipulation on the sea floor. (See the article in this issue “Instrumenting the sea floor,” which starts on page 101.)