There are several spots in the Eternal Ocean, the most notable of which is the space under the island of Maikrecht which is the lowest flying of all the continents. Due to the intensive mining, it is expected that the continent will eventually fall, and it is low enough that it impacts the tides. Corsairs do not sail those waters, since when the island falls it is large enough to surely kill any unlucky soul beneath it, to say nothing of those still on the island.