This is a water world start map (no player built stuff yet) with islands spread out. They are there, but you must go out to find them. Their is a forested island at -758, 77, -1745 and a sandy island with an underwater temple right next to it at -655, 64, -2787. (see images) the world does not have a funny waterfall border, it goes on like a real ocean would. Has lots of underwater canyons look.
You start out underwater, swim up fast :)
Java 1.12.2