Between each of the continents, there are vast swaths of water in the form of bays, channels, and oceans, on which the Law of The Sea only applies. Water hexes can only be traversed by building a Dock or Shipyard and building a vessel to navigate them.
Fishing Fleet
Transport Vessel
War Galleon
On the Map of Osterra, full ocean hexes cannot be held yet, but Fishing Fleets may be utilized on coastal hexes to increase yield of Food every season.
The following are the prominent (discovered) bodies of water in Osterra
Frozen Sea
Sea of Shadows
Savage Sea
Gulf of Lost Kings
The Grey Sea
Barren Bay
Sea of Fate
Manticore Bay
Cimmerian Sea
The Dreaded Depths
Tian Shi