One of the four great planar paths, the River Oceanus runs through most of the Upper Planes, allowing for transportation between them much as the River Styx does on the Lower. Starting in Thalasia, the ocean-covered lowest layer of Elysium, the river winds through the other three layers of that plane as well as across the Beastlands and Arborea. Some claim it may be slowly extending its way into Ysgard as of late as well, with rumors often circling about a transient connection with the Gates of the Moon, Selune's realm in Asgard.
Though the river is used often, both for basic travel and the shipment of trade goods, it isn't without its quirks. One small difficulty some may run across in trying to navigate the river is its odd meandering path throughout the three planes. The river does follow a general course, from Thalasia up through the layers of Elysium, across Krigala and into Olympus, ending in Ossa, with tributaries branching off into each plane as well as the Outlands. However, the specific path never seems to be the same one twice, and the locations visited within each layer are never quite in the same order. Even with this slight varience, however, Oceanus is still a much more reliable path than the Styx.
- Planes of Chaos - Book of Chaos, pgs. 7, 116
- The Planewalker's Handbook, pg. 12