Soak your hair w/cold water before you swim, slather on some conditioner if you want (it prevents the chlorine from reaching the hair shaft) and wear a swim cap if you can. After swimming, rinse with warm water for a few minutes, then with cool. Chlorine doesn't make your scalp dirty, so there is no need to wash with the bs. If your hair feels dry, straw-like, etc. try using some natural oil, like coconut or what have you, rubbed into the ends to keep them moisturized.