The Tastston Ocean is one of the largest in Eterinin. Covering the entire western coast of the tri-continent of Edhen, Sama, and Dolinde it stretches from the Northern to the Southern White Plains and ends inside the Onisa Isles on the west. It's western border is fairly ambiguous, and generally is considered to end within the mid point of the Onisa Isles in the south and at the governing range of the Otopians in the north.