Whether it's for hygiene purposes, not wanting your hair to turn into straw or an attempt to be a little more streamline and therefore go a little fast, a good number of people who swim at the pool wear a swimming cap.
And you certainly get some pretty interesting swimming caps at the pool. The children have some fun ones. Caps that look like fish or sharks, with little fins on the top and side. A couple of the little girls I teach have got these kinda cool, retro, little old lady shower cap style hats that they wear.
There are several swimmers who clearly want to show off that they once (upon a time) swam a triathlon, an outdoor 5k, for some sort of club or even just in some sort of fun/sponsored swim. But then I kinda get that because if I one day manage to swim the channel, I might just spend the rest of my life wearing - in and out of the water haha - the official Channel Swimming Association swimming cap (beaming with pride each and every time).
There are also the people who wear the cloth caps. What's the point in those? Do they even keep your hair dry? And I'm pretty sure there is one lady who actually wears a shower cap? It looks like one of those transparent caps you get when you dye your hair. (Not that I've ever done that... cringe).
But me. Well I'm the man in black and so I just wear my plain black speedo silicon swimming hat as always. Well at least I did. However, recently I went a little mad and bought the jazzy little black, yellow and green number in the photo above! Which is actually fairly tame and yet also a little too flashy for my tastes haha I'm not sure what I was thinking. I was pretty happy just being the man in black.