Change into swimming costume. When hair is dry, apply conditioner/coconut oil to the ends. Wet hair in the shower, so your hair absorbs normal water, rather than chlorinated water. Plait so you can fit it in to a swimming cap.
Add a few drops of argon oil to your conditioner for super silky hair. I apply conditioner to my hair, then wash my swimsuit with shampoo, leaving the conditioner in my hair for longer (chlorine can make your swimsuit disintegrate really fast!).