The Water Walking spell 'enables you to cross the Storm River from any space in the outer region to any space in the inner region, or vice versa.' Does that mean to the space directly opposite the one you're in, or any space in the opposite region?

Any space directly opposite. e.g. If you are on the Sentinel space and cast the Water Walking Spell, you may move to either the Hills or the Hidden Valley. (Extend the space dividing lines across the river to see which spaces they would disect - these are the spaces that you can move to!)

Ell.

Is their Errata clarifying this, verbiage on other cards (example ferryman) State adjacent or across, the waterwalking card states ANY to ANY

Curben said:

The Water Walking spell has this wording in the original English version (maybe you're quoting from a different language):

Cast on yourself at the start of your turn, before you move. You may cross the Storm River as if you were using a Raft.

Talismanamsilat explained how you should interpret the "directly opposite space" concept, which is not 100% clear from the Rulebook.

I don't see anything strange in the above text, at least nothing that differs from the Boatman Adventure Card or other Raft-like effects.

This was the third edition apparently