I didn't read this becuase it was a bit of a wall of text. :)
But as an avid sea kayaker, I can say I experience this all the time. And it's super wacky when you've got rebound waves coming off a rock wall, and 6 footers coming in from the North Atlantic.
Effectively , everything becomes unpredictable. You are sitting on the crest of a wave and go to put your paddle in and... there is just no water there. So you put force into a stroke and there is no resistance at all causing some tippiness and what not.
I think Super Mario 2 being what it was really messed me up.