@Crossway In the long tutorial on MapMagic, Denis explains how to do this at about 6 minutes in. Essentially you need to start with a Raw Input height map of your island that you scale to the size of the 25 tiles. Then it can be surrounded by water. I'd imagine its possible to do without using the Raw heightmap input by creating a filtering that pushes the terrain down around the outside. But it sounds like too much messing about. I'd just use the Raw image input. The tutorial is long but it really will get you going nicely with MapMagic.