This one is the Desert Island (30x30), a tiny little clump of islands with nothing but a handful of palms and rocks. I'd say this would make for a pretty dire place to be shipwrecked and an obnoxious place to fight enemies that can easily move both on the land and in the water.
Your alternate versions of this map are Low Tide and Barren! The Low Tide variant connects the little pieces of land now that the water is lowered, giving you a bit more empty space to play around with. Or, maybe your players wash up here at low tide and fall asleep on the shore, waking to the regular version of the map and much less space to work with. Then there's the barren variant, where your players can't even have trees and grass any more, just sand and rocks. Now this is a bad place to be- good luck.