This survey, led by Galway-Mayo Institute of Technology (GMIT) and the Irish Whale and Dolphin Group (IWDG) was conducted on board the Marine Institute’s R.V. Celtic Explorer as a dedicated survey between 18th and 31st August 2009. The survey area covered waters over the Porcupine Bank, Porcupine Slopes and Irish Shelf and slopes to the west of Mayo. The survey track was designed to target deep-water canyons on the slopes of the Porcupine Bank and the Irish Northwest Shelf. The main aims of the survey were to carry out visual and acoustic surveys of cetaceans, visual bird and macrofauna surveys, the deployment of the M6 weather buoy and two Deep C-PODs for acoustic monitoring, The survey vessel travelled at an average speed of 8 knots while on transect, except in heavy swell. The ship spent from 08:30 – 18:30 each day on visual and acoustic transect, and from 20:30 – 08:30 altered between steaming at 8 knots and being stationary while conducting CTDs, water sampling and plankton hauls. Visual and acoustic surveys for cetaceans were conducted. A towed hydrophone array was used and two Deep C-PODs were deployed during the survey. One POD was deployed on a benthic mooring in 1500m of water, with the sensor facing upwards towards the surface.A second Deep C-POD was deployed at 500m water depth on the mooring for the M6 Weather Buoy. The buoy was moored in 3200m of water. The POD was deployed with the sensor facing down towards the seabed Acoustic data from bottlenose dolphin (Tursiops truncatus) encounters were recorded using passive acoustic techniques and provided to a PhD study (based in University College Cork and funded by IRCSET). Visual seabird surveys and megafauna surveys were also conducted on this cruise, as well as the deployment of an argo float. As the primary purpose of the cruise was to record the distribution of cetaceans using visual and acoustic techniques, oceanographic work was conducted only after sunset. 11 oceanographic stations were sampled. Zooplankton samples were not taken at every station due to time constraints (only stations 1, 2, 8, 9, 10, 11). CTD data however was collected at all stations The main focus of the survey was to conduct a habitat specific survey of deep diving cetaceans, particularly the enigmatic beaked whale species.