Can Tideturner target a unit at the same location (its own base) to satisfy targeting requirements?

Ruling: No, Tideturner cannot target a unit at the same location. The card specifies "another location" in its text, meaning the target must be at a different location than where Tideturner is played.

Nuances:

• The ability is optional ("may"), so you can play Tideturner without activating the trigger at all