As noted in the NY Times, Google Earth recently added topographical seafloor data. So now, in addition to flying around Mount Everest, you can also swoop low across the Mid-Atlantic Ridge. It’s an important shift of view, because it gives you a visceral appreciation of the different forces that shape the underwater surface of the earth.
For instance, you can understand Darwin’s reasoning about the formation of atolls. In his day, there were various arguments about atolls being sea mountains caught in the act of rising or subsiding. But Darwin said, essentially, what are the odds that all these mountains, scattered across the whole Pacific and Indian oceans, all happen to be exactly the same height, which is to say, coincident with sea level? And why are they all associated with coral? There is indeed a mountain subsiding here, but it’s being augmented by a living crown. It was an impressive leap of reasoning… tiny polyps keep mountains growing in the ocean like gigantic plants.