Minecraft wiki entry for Defeating_an_End_city, associated text: To cross a gap between islands, build a bridge, sneaking as you go to avoid falling into the void. Ender pearls can also do fine. Don't worry about them falling into the void, because they won't teleport the player if this happens. However, be very careful to not let them hit the sides of islands, as you will be teleported over the void, and it is very hard to save yourself from losing all your gear, and possibly valuable loot. This is more of a problem when traveling large distances. Try not to do this too much, as this will cost you ender pearls (though you can easily gain more by killing endermen if you run low).