As long as the globe is one closed mesh, the boolean subtraction should work. Are you sure there's no holes in the mesh or anything? Sometimes using displacement-to-poly conversion leads to a messy tesselation, which could mess up the actual boolean operation, but I'm not entirely sure if thats the case at your end, since…
All, I have converted a displaced sphere to geometry (it's a globe with raised continents). I now wish to select and delete the "ocean" part. I have tried a Boolean subtraction with a smaller sphere with no success. In fact I've been trying every mesh rebuild, history delete, whatever to make this Boolean happen. So now I…