Out of curiosity, what are the chances there could be an update that would let it work with mod water tiles? I don't know what's going on under the hood, I'm just wondering because I would love to use this with the Alien Biomes mod, but there's an error on startup when I have both enabled. Even if it's not possible to have the ores spawn over mod water tiles, I'd love to be able to use them both.

Here's the error I get, if it helps:

"Failed to load mods: Water_Ores/data-updates.lua:3:attempt to index field 'sand-source' (a nil value) stack traceback:
Water_Ores/data-updates.lua:3:in main chunk"

facepalm
I copy pasted the data-updates file from a different mod, and left in the code for alien biomes that it used. Probably because I was planning on adding compatability with alien biome water tiles, except it doesn't add any.

Fixed version uploaded.

Awesome! Thanks heaps!