Koreans don't like water. Well, it's not that they don't like water or it's properties, but they're afraid of it. Their afraid of emerging their bodies in it and then drowning. It is a peninsula country, a country nearly entirely surrounded by water, and its citizens are petrified of swimming. How a water-locked country does not value swimming is beyond me.
Before I came to Korea, I took my ability to swim for granted. I don't think I'd even ever been asked if I could swim before I arrived in Korea. From a young age, Americans are coaxed into the water. As toddlers, even as babes, parents teach their children the basics of swimming. I am by no means Michael Phelps, and by no means, an excellent swimmer, but I can do all four main strokes, and I can get myself from here to there without drowning. Whenever I think of my swimming abilities, I'm always reminded of an embarrassing moment in my swim team years. One where in the midst of a competition, I, who incidentally wore no goggles, mistakenly swam under and across all four lanes only to end up beneath another competitor in the wrong lane, oh so very far from my own lane. So engrossed was I in the race, I had no idea of this embarrassing mistake I'd made until I came up for air and found a person above me.
There is only a short summer in Korea, few pools, and fewer swimming lessons. Korea is a modest society, one in which being half naked is not smiled upon. Swimming is a large part of American culture. If you say you can swim in a conversation, people don't generally gush over your amazing talents. It's pretty much assumed. In Korea, saying you can swim is akin to having super human powers. No one knows how to swim. That's an exaggeration; a minority of Koreans can swim.
All swimming pools require swimming caps. If you don't have a swimming cap, a hat is acceptable. I'd never worn a swimming cap before coming to Korea. The idea of swimming caps isn't inherently a bad one, but the way in which Koreans wear their caps, completely defeats the purpose of keeping the hair out of the drains of the pools. Hats do nothing to keep hair from floating its way to clogging the pool, and often caps are only worn on the top of the head allowing the hair to freely languor in the water. But the rule is never-the-less strictly enforced.
It should also be noted that Koreans do wear swimsuits, but never by itself. It is always accompanied with baggy clothing. Why, I do not know. Because it is a modest country, because it is their way, because that is how it has always been done.