Kayak Angst

So I'm reading Mary Roach's latest book, Packing for Mars. It's a tour through the little-known aspects of putting humans into space. For instance, if you've always wondered how astronauts go poo in space, I'd recommend Chapter 14 -- you'll find out more about this topic than you could ever possibly want to know.
One of the joys of Roach's writing is that she is easily distracted from her main thought and often strays from her topic to follow an obscure notion or fact down a rabbit hole to see where it leads. And thus on page 67, while discussing the phenomenon of "the rapture of the deep," a feeling of calm and invulnerability that can impair a diver, and the possibility of a similar impairment affecting astronauts, she adds the following footnote:

Every mode of travel has its signature mental aberration. Eskimo hunters travelling alone on still, glassy waters are sometimes stricken by "kayak angst" -- delusions that their boat is flooding of that the front end is either sinking or rising out of the water.

Kayak angst! Who knew? Well, Google Books did -- here's a whole bunch of references to it. And so did Paula when she wrote this blog post two years ago describing how she found the term in a book she was reading. And since I've read the same book and don't remember coming across the term at all, I'm getting a little angsty about my memory and comprehension skills right now.
Kayak angst apparently occurs in calm conditions, but a strong wind, a quick current, and big waves, that's what gives me kayak angst! It makes total sense, of course. It's the same reason why pilots sometime slowly and calmly fly their planes into the oceans on clear sunny days. Staring at the same unchanging horizon for hours can create vertigo and cause the mind to think you're falling when you're not. Sort of the same feeling I have when I'm on a ladder.
You can buy Kayak Angst t-shirts if you want to, although the reason why anyone would want to advertise that they suffer from a niche psychotic malady eludes me.