Grwn Sea
The Grwn Sea (pronounced "Groon") is a vast ocean south of the Dudlingia Principality. The Agripidian Grand Duchy touches on the Grwn Sea to the southeast and the northern tip of the Coviorian Republic to the southwest. The Grwn Sea is wild and dangerous, filled with tempests and powerful storms. The surrounding lands are often battered by gales, hurricanes, and tsunamis.
The Grwn Sea is deep enough that it contains gargantuan octopuses and colossal krakens. That, along with the weather, effectively stops almost all Ocean Travel. The one exception is the route between Nergentiapu and Haverenil run by Naga at exorbitant prices.
Given northern Agripidia's proximity eastern Dudlingia, one might expect a trade route between those two locations. However, that would take ships dangerously close to the Sunken Ruins of Tinuviel. Not even the Naga sail there, and if asked, will whisper of dark evil sea monsters, twisted by the vile magic that sank Tinuviel.