Originally posted by magilla666:

The boundaries of oceans seem capricious, at best. What's the rationale for making a patch of water "ocean" or some land biome? There are times when I'm on the water with no land in sight, but I'm in Meadows. I've also been in spitting distance of land, but I'm still in Ocean. And which land biome you're in also seems random. It's not what you're pointed at- that's easily disproven. It's also not the land you're closest to. So is there some rule for predicting, at least roughly, if some patch of water will be ocean biome or a terrestrial biome?

well the game is procedurally generated, so the game arbitrarily decided that pond is an ocean biome.
In reality, oceans are bodies of water that "surround" continents. Seas are normally large bodies of water, lake sized and up that are surround by land but connect to the ocean. There is the one exception, I think, which is the Sargasso sea? Which is just a pattern of oceanic current.