Deployment of an acoustic Doppler current profiler using a low-drag subsurface multisensor flotation package: design criteria and results

An upward-looking, acoustic Doppler current profiler (ADCP) which was deployed twice for periods of three months at a depth of 500 m in 800 m of water is discussed. The ADCP was mounted in an oblate-spheroid fiberglass package to minimize drag and consequent beam tilt. The package included flotation, two acoustic releases, ARGOS transmitter, radio transmitter, and a flashing light. An Aanderaa current meter was mounted on the package to monitor CTD parameters. Platform inclination in the first deployment averaged 1° with a maximum of 2.7°. The 75-kHz signal reached the surface with a total of 64 8-m bills, of which all except the top nine gave an excellent data return. The design of the package and a summary of the oceanographic results are included