Potlatch

The rock slab to the boater's left is undercut. The rock to the boater's right creates a scary fan/rooster tail. The reversal is somewhat strong at ~4' and above on the put-in gage.
This splat wall is one of the only real points of interest in the long paddle-out of the Potlatch Canyon. I'm past the days where I'll take a playboat down that stretch (more due to comfort issues than anything), but if you're in a squirtable boat, you can spend a few minutes here enjoying yourself...