Voidsea
From Andorith
The Voidsea is a seemingly limitless area of space outside of the breathable atmosphere of the planets on the Andorith plane. It seems to have its own pressure, as ships that travel though it do not need to worry as much about explosive decompression as they would on Earth's plane. Many of the most primitive voidships were built with simple metal and canvas.
Leylines crisscross the Voidsea and are a main way of traveling though it, but are not visible to most individuals. See Voidsea Propulsion for more information.