The Straits of Darkness are a notable shipping hazard that connects the The Endless Sea to the The Bitter Sea. It is one of the main trading routes between Kingdom cities on the Far Coast like Crydee, Carse and Tulan and their other Western Counterparts within the Bitter Sea. They get their name from the dangers that await anyone who attempts to sail through them in the winter.
During winter, the Straits become encased in thick fog. This fog makes the many rocky outcrops, both visible and below water, of the Straits impossible to view until a ship had nearly crashed upon it. Winds from the North can help remove the fog, but replaces it with snow from the Grey Towers. Prevailing winds can either blow you back out to the Endless Sea, or right into the rocks of the Straits. Several currents from both the Endless Sea and the Bitter Sea converge in the Straits, making it hard to keep a ship aimed in the right direction if fog is present. Water spouts throw water into the air, spinning madly before the sudden burst ends and the water falls back to the surface below.
During the winter, Midkemia's several moons all arrive in positions in the sky that cause crazy variations in the tides. All of these factors lead to the dangerous nature of the Straits in the winter. Only the most skilled of captains have a chance at surviving was is essentially several days of sailing blind, including Captain Amos Trask.