If you want to see a command block to set your spawn point on an island, you've come to the right place. your on an island, and if you fall... you die. I have fall-proofed the bottom of the island with bedrock so the only way your getting down without falling is creative, but The map is required to be in survival until you have completed the map. then you can do whatever you feel like. But this is meant for 1.7.10 or up, because I made it on 1.7.10.