GEBCO uses deepwater survey data to produce bathymetry maps and grids. Published maps appear complete but are in fact based on very little data. Only a portion of the deep data that could potentially be put to use is contributed to the public domain. All would benefit were more data submitted to data centres.

The watery grave of the German commander, has been discovered off Orkney.

"Technology has improved dramatically in the last ten years, but the deep oceans are just so vast," Gardner said. "Something else has to be done."

A survey of ships and other craft lost during Operation Neptune provides not only an inventory of sunken artifacts but also a key to remembering D-Day.

Ocean-mapping experts reconstruct what happened when allied forces stormed the beaches of Normandy