Certainly, when I was very young, I learned that receding water like that meant a tsunami was on the way. But in today's world of careerist knowledge bases lacking vast areas of what used to be considered standard practical life knowledge, what, maybe 10% max, of the population would know this? I'm perhaps being too generous.
Yeah, I'm sure you're correct, but I was thinking of it more in terms of a gut-level survival thing rather than an intellectual knowledge.....like when someone rears their arm back and you jump back instinctively because you know a punch is coming.....I'm just surprised to see the people in the photo not even looking out at the strange sight....but I wasn't there and I don't want to get myself in trouble by implying criticism of those that were there....just speculating.