This survey, led by Maynooth University in associated with the Geological Survey Ireland, was an investigation of submerged ridges off the west coast of Ireland. Linked previously with ice movement, these ridges can help reveal information on the dynamics of the British Irish Ice Sheet during the height of the last glacial maximum, around twenty thousand years ago. The cruise was also a training exercise in marine research for recent graduates from Cork and Dublin City Universities. Gateways 3 voyage is a continuation of previous research cruises to improve our understanding of ice drainage routes (iceberg “gateways”). The survey took place off the west coast of Ireland on board the Marine Institute's R.V. Celtic Voyager. GATEWAYS III; Internal structure of the ridges of the Porcupine Saddle: The objective of this survey is to understand the formation of the Porcupine Saddle ridges and study their potential origin as subglacial features from the last glaciation.