Also nowadays we have such accurate satellites that we can actually see the tiny increases in elevation of the sea level that reflect the topology of the sea floor.

Satellites notice the tiny “water mountains” which indicate the topology of the sea floor, and then they scan the place better with equipment on boats.

theguardian.com/…/more-than-5000-new-species-disc…

But yeah, I really think “water mountains” is a bit on a exaggeration to that phenomena.