In keeping with the theme of this issue, this article focuses on the sacrality embedded in the depiction of the seas in the medieval Islamic KMMS mapping tradition. Teasing apart the depictions, this article analyses the sacred dimensions of the fives seas that make up the classical KMMS image of the world: Baḥr al-Muḥīṭ (the Encircling Ocean), the Baḥr Fāris (Persian Gulf-Indian Ocean-Red Sea), Baḥr al-Rūm (the Mediterranean), Baḥr al-Khazar (Caspian Sea), and Buḥayrat Khwārizm (Aral Sea).