Oh, it’s very much a cartoon meme, even if it also happens in reality.
Various replies here indicate that it’s “common”, but not universal. Also that it sometimes (often?) indicates a health problem that should be treated. Maybe that’s why I haven’t yet encountered it in person.
An incoming tide compressed between the banks of a river can (in some locations) produce a significant wave. The Bay of Fundy is an extreme example, and it’s not even a river.
But I haven’t heard that the French Olympics are using a river for their surfing.
“How comes nobody today asked WHERE he is?”
Because we already know. He’s taking a break from writing by climbing Mont Onis.