The incompleat current meter

Engineering and construction activities in the ocean require information on currents over a wide range of speeds, depths, and time scales. Many current measurement programs are hampered by lack of complete integrated systems to acquire the necessary data. Measurement accuracy is frequently degraded by mooring motions. Mooring suspensions for near-surface and near-bottom measurements are difficult or incompatible with other requirements. Data recording techniques limit deployment periods or undersample processes. Telemetry of data or system status is rarely available. Unlike scientific studies, which may choose to focus on some aspects of the currents at the expense of others, engineering studies must determine all those features of the currents which will impact the intended activities or structures. Examples of the effects of all these instrument limitations on particular studies have been encountered in recent EG&G studies. Methods to surmount these difficulties have been developed, but better current measurement systems could provide considerable improvements.