The main objective of RRS Discovery Cruise 323 was to carry out the first deep sea field trials of the National Oceanography Centre, Southampton (NOCS) developed Autosub6000 Autonomous Underwater Vehicle. In addition, we took the opportunity, working with engineers from Proudman Oceanographic Laboratory (POL), to carry out deep water testing of integrated two way acoustic and satellite communications systems. NOCS benthic biologists also carried out seabed sampling operations at the base of the Whittard and King Arthur Canyons. As far as the Autosub6000 operations were concerned, the objectives of the cruise were completely met, with 8 dives, lasting 60 hours total and running for 278 km, to a maximum depth of 4553 m, and without faults. The POL tests of the acoustic and satellite systems were a success, and the NOCS benthic biologists successfully obtained Mega core samples at the base of the Whittard canyon
