Start Game -> Local Play
Create 2 new worlds1. create a second world in single player
Log into the second one,2. and create a ship.try to access that world
Exit to main menu
Log into the first world, and its still the same world.3. mostlikely the older world will be loaded in if that one was accessed before
---
Exit to main menu and try with any number of worlds.the game loads into the world that is specified in the first line of the server.cfg file
It will always default to world0.it even creates that world on game start imidiatly if it doesnt exist