The underwater terrain which encompasses the Hawaiian Islands gains its unusual hummocky topography from the many slumps that have taken place for millions of years.

But before returning to the surface, they made a survey of the underwater terrain.

It was not his job to examine this underwater terrain for signs of the crab colony.

Overview for underwater terrain, data formats, etc. (vterrain.org)

As well, the reef is often marked with floating buoys in order to help guide inexperienced divers along the underwater terrain.

After the Hammer of Eden it was used to map the new surface of the Earth, as well as underwater terrain and new ocean currents.

Thanks to multibeam sonars, sea floor mapping, and positioning systems, fishermen could suddenly exploit deep underwater terrains that previously had been unknown.

The player has to steer the Spycraft, a Spy Corps vehicle, over air, sea, and underwater terrains.

A lot of islets and islands are built up of limestone, and their underwater terrains are cracked with caves and holes.

Yes, but the underwater terrain there is a maze of reefs, caves, and ledges.