Ekkaia, sometimes spelt Eccaia and also known as Vaiya, the Outer Ocean, the Outer Sea, and the Encircling Sea, was a vast, cold and dark ocean that completely surrounded the world of Arda, at least until the Undying Lands were removed from the "circles of the world" in the cataclysm near the end of the First Age.
It flowed completely around the world, forming a sea below it and a form of air above it. Arda is described as having floated on Ekkaia, like a ship on a sea. The Sun passed through Ekkaia on its way around the world, warming it as it did so. Within Ekkaia lay Ilmen, the upper atmosphere, and Vista, the lower atmosphere. At sea level, Ekkaia met Belegaer at the Helcaraxë. Ekkaia itself was enclosed within the Walls of the Night.
Ulmo, the Lord of Waters, dwelt in Ekkaia, below the roots of Arda. Ekkaia is described as extremely cold: the strait where it met Belegaer in the northwest of Middle-earth, the Helcaraxë, was filled with ice floes and icebergs. Ekkaia cannot support any ships except the boats of Ulmo; the ships of the Númenóreans that tried to sail on it sank, drowning the sailors.
Ekkaia apparently disappeared after Arda was made round, although it may have been changed into the upper atmosphere of the world.
|Seas of Arda|
- The New Tolkien Companion
- The Complete Guide to Middle-earth, by Robert Foster
- The Atlas of Middle-earth xi, 38-9