Cartesian Channel

The Cartesian Channel is a wide body of water that connects the much colder Magellan Sea with the more temperate South Harbinger Sea. This junction of hot and cold water produces tremendous cross currents in the area, making navigation of the channel particularly difficult even for large vessels. The channel was first navigated by Havanite explorer Victor Kent in Y1543 with the help of Velocitan cartographer Avery Nedalus and his fleet of Marlin-Class Schooners. 
The channel is the site of many naval battles between the Iron Coalition and the Pax-Viribus Theocracy, as the city of Bulwark is the crown jewel of the PVT, and makes for a tempting target. Unfortunately the channel's wildly varying depths and banks make for tricky navigation by larger vessels, and there are many ships in various places that have run aground over the decades of battle that prove too costly to retrieve.