Two Halves

From gronkfinder

The Two Halves is a large island within the Blacksand Archipelago. Originally a single volcanic peak rising from the Kilche Sea, at some point in the distant past the island was split in two in a jagged line down the middle. In most places this channel is less than a hundred feet across, decreasing to twenty at the narrowest. The cause of this calamity is unknown, though the pirates of the Blacksand League tell innumerable stories, ranging from fights between monstrous sea creatures to magical experiments gone awry or divine intervention.

Freebooter's Folly, an annual race held by the pirates of the League, includes a dangerous section through the gap between the Two Halves.