RRS Charles Darwin Cruise 121, 20 Apr-4 May 2000. Ocean Engineering Division instrument trials cruise over the Goban Spur, Pendragon Escarpment and Porcupine Abyssal Plain

The objective of this cruise was to test a variety of oceanographic instruments under realistic field conditions. These instruments included:- USBL acoustic navigation system; Inverted acoustic navigation system; SHRIMP deep-towed camera system using fibre optic tow cable; Scatterometer profilerChirp profiler; CLAM cable monitoring system; Autoflux meteorological measuring system; UV nitrate sensor; Fibre optic pressure and temperature sensor string; SUMOSS hyperspectral spectrometer system Most of these instruments require a water depth of several thousand metres for normal use and this dictated the choice of work area. The Porcupine Abyssal Plain is the nearest place to Southampton offering these conditions. All the instruments apart from SHRIMP and the scatterometer produced useful test results demonstrating the advantages of this type of cruise. Those instruments that were not successfully tested were handicapped by a lack of preparation that was aggravated by the cruise taking place earlier than initially requested.