This is a great data set for global bathymetry from NOAA’s NGDC (National Geophysical Data Center). I really enjoy looking at the raw hillshade in grayscale, taking that single layer and trying to figure out how our world is put together, what influence moving plates have over topography and bathymetry, what influence massive bodies of water have over the rock and sand and soil beneath them. Can you figure out where the land ends and the ocean begins? It’s a bit more difficult than if we have visual hints to guide our eyes, but with a high enough resolution image, you can probably determine shorelines pretty easily. There are some great clues tucked away in the landscape/seascape. I still think it’s amazing the amount of information you can get out of one file. The source here is one global DEM, from which I created a couple hillshades, a topographic color ramp, and a bathymetric color ramp. That’s it, and the last image just shows these layers in a globular projection with a slight shadow effect courtesy of GIMP.