Walls & Bad Eddies
Glad you survived, but probably not as glad as you are.
Anyhow, that recalls two experiences with similar cliff-sucks.
Doing the Day Run above Moab at about 25k (maybe over-casual about it), I got too near the cliffs river right and was caught in a circular slam thing. Wham and around and wham and around, etc. Scary. I was in a small double oarframe cat. Really quick turnaround: I screamed High Side and she jumped, then NO— THE OTHER HIGH SIDE! I got in a lucky stroke in about the 4th or 5th circulation, that punched us out into the current.
At Bedrock Rapid in the Grand Canyon we had a few boats swept left, down an angular rockbound channel bordered with vicious keeper eddies. Our biggest boat— an 18-ft. Jack's El Tigre, got spun and slammed repeatedly before busting out, with people thrown off and retrieved: carnage. Right after that a mini-snout rig (25 ft. cat with motor) got buggered in the same spot. They broke a couple oars and sheared the prop off their motor.
The power of those things is incredible.