Global Bathymetry GEBCO
The General Bathymetric Chart of the Oceans (GEBCO) is a global bathymetry dataset – developed from multiple sources by an international group of experts. The resolution of the dataset is at 30 arc-seconds (approximately 1km). It was released in 2014 – based on a previous version from 2008. Traditionally, the GEBCO dataset have focused on deep-water areas (i.e. beyond 200m water depth), however with the recent versions many shallow water areas have been added based on contributions from national hydrological offices.
Read more on gepco.net: [1]