Given the lack of any other extant nation along the coast of the Great Ocean, maritime trade and travel along the far western coasts is not commonplace (aside from that within Zeüm itself). Zeüm trades with the nations of the Three Seas through its southern ports and the straits separating the Ocean from the Sea of Oncis. The only major use of the Great Ocean for a military campaign was during the Cûno-Inchoroi Wars, when the Nonman Mansion of Illisserû assaulted the Incû-Holoinas by sea. The attack was not successful, with most of the invading force destroyed in the Battle of Imogirion. The remnants of the fleet were sunk on the way back to the Three Seas by storms, demonstrating the dangers of entrusting any major military campaign to the vagaries of the weather.