The General Bathymetric Chart of the Oceans (GEBCO) is working to map the floor of the global ocean. The oceans cover over two-thirds of our planet but it's often said that we know more about the shape of the surface of Mars than we do about the bottom of our own ocean.
The General Bathymetric Chart of the Oceans (GEBCO) operates under the joint auspices of the IOC and the International Hydrographic Organization (IHO). It involves a group of international experts in seafloor mapping who are working together to develop a range of bathymetric data sets and data products for scientists and resource managers.
Useful links:
GEBCO website