On the Gulf of Mexico
Vast unexplored areas of the ocean have now been mapped with new satellite data and scientists have discovered thousands of previously uncharted seamounts in addition to an extinct spreading ridge in the Gulf of Mexico.
… Seamounts, which are at least 1,000 meters (3,200 feet) in height, were also prominent (not in the Gulf) features in the new map,
NOAA Gulf of Mexico Map Tools (many).
Here are just a few:
Computer-enhanced multibeam bathymetry map of the northwestern and northern Gulf of Mexico continental shelf and slope.
West Flower Garden Bank in GOM
On the Seafloor, Global
This map shows the spreading rift (Africa to South Asia)