Sea of Torments

From Glen Cook Wiki

The sea dividing the northern lands from the southern lands. Although frequently stormy, it appears to be no more than two to three hundred miles across in places - the crossing from Opal, on the northern shore, to Beryl on the southern shore, can be managed by boat in three days of fair weather.

At the eastern edge, the Sea ends at the Straits of Angine. It is implied that there is a similar narrow crossing somewhere to the west as well.