Wear a cap.
When you go swimming, what can you do with your hair? Answer: Get it wet and deal with it -- or don't go swimming (and if this is in school, you'll have to deal with those consequences -- which are probably worse than getting your hair wet).
You are a troll. You are no 13-15 year old and your avatar is not you.
Theres something girla wear on thir hair when thay are swimming its plastic