Terrain data that represents earth features for a geographic area is received. The following meshes are generated based on the terrain data: (i) a water surface mesh including a first plurality of geometric primitives and (ii) a water bottom mesh including a second plurality of geometric primitives. Portions of the water bottom mesh appearing above the water surface mesh are identified. At least one of the water surface mesh and the water bottom mesh are corrected to cause the water surface mesh to appear above the water bottom mesh.