Is chlorine alright for my watch if I where it in the pool?
Is chlorine alright if I wear my Apple Watch series 3 in the pool?
Apple Watch Series 3, watchOS 6
Question marked as
Yes. The Series 3 can be used in a pool without any issues. You can rinse it off with fresh water after getting out of the pool if you want to.
See here: About Apple Watch water resistance - Apple Support