This model is usable in any scene from low-poly mobile games to high-poly rendering.
Three objects: terrain, sea and sea bottom.
You can easily change mesh resolution in 3ds max: simply change Turbosmooth iterations. FBX and OBJ exported with 3 iterations, 3DS with 1 iteration. Preview images made with 3 iterations in Marmoset Toolbag (included).
Textures used: -island diffuse and normal map: 4096x4096 -height map (for displacement): 4096x4096 -sea normal map: 2048x2048