Alright.. so so far the sentiments are NO REPLACING. Better to re-use and make new ones. Replacing will probably be cumbersome and prove to be an ungainly process. Now, The more diverse the islands are, the more interest there will be. Islands are completely randomized in the real world. Thus you can make anything you want, as long as it conforms to the laws of physics and is resonably sane and appropriate for the setting. coastal caves, cliffs, flat beaches, lagoons, you can have them all.