anyone ever find anything under any of the lakes. theres gotta be something under all that water.

someone

Fish - lots of fish! ;)

The only place I found something else was outside of Collasium - Talrik's treasure.

I love swimming in this game! Lots of fun!

Wyv

There's another treasure chest at the bottom of the Lost Sea, along the eastern shoreline. Not much in there by that point in the game, but you never know...

Plus you can always find all sorts of sea denizens to boost your experience! Crabs, sharks, Dartha Eels... tasty, for sure.

I also found a fairly good sword at the bottom of the underground lake in Dragon Spire.
The sword is very deep, so get air before you go down.