Why do male swimmers wear swim caps?

Question

I always wondered, why they wear swim caps?

I know women do because they dont want their hairstyles to get messed up, they dont want this or that... but guys... why?

Answer 1

 They wear swim caps to protect their hair from harsh chlorine, to stay warmer in water, for more visibility in open water, to keep hair out of their faces, and for hydrodynamic streamlining

Answer 2

to get faster in tthe water