Darcos Sound was a sound of water between Charis Island and Silverlode Island, connecting the Charis Sea and Eraystor Bay in the north to the Middle Sea in the south.

In the Year of God 892, the Battle of Darcos Sound, in which the Royal Charisian Navy overwhelmingly defeated its Corisandian, Emeraldian, and Chisholmian counterparts, was fought in the area. As a result of his conduct in the fighting, Midshipman Hektor Aplyn was created the Duke of Darcos, ruler of the Darcos Sound area. (OAR, BSRA)