INSS Bathymetry Survey Atlantic Ocean. Ireland's territorial seabed reaches more than 600 miles out into the Atlantic Ocean to waters of more than 4,500 metres in depth. The Seabed Survey aims to map the seabed collecting detailed bathymetry (water depth) data and knowledge of the nature of the seabed and its overlying sediment. In addition, Magnetic and gravity techniques are helping to evaluate the nature and structure of the deeper geology. This cruise is concentrating on waters in Zone 1 between 0-50m off the Irish coast. Mapping Ireland's seabed resource.