scary looking swimmers

Ok they're a little scary at the moment but they are awaiting hair, and hair is the problem, I just cannot decide what to do about it.  I know I don't want wool, I have thought about swimming caps but they would still need a little bit of hair.  If anyone out there has any ideas I would be grateful as I am thinking about doll hair morning, noon and night now!

I should add that these girls are inspired by the 'Battery rocks swimmers', a small (unsurprisingly) number of all year round sea swimmers who swim from Battery rocks.  At the moment I can only dream of ever being hardy enough to belong to this elite group!