Waterproofing

from anypats provided link

Is my Apple Watch waterproof?

Your Apple Watch is water resistant, but not waterproof.* For example, you may wear and use your Apple Watch during exercise (exposure to sweat is OK), in the rain, and while washing your hands.

* Apple Watch Series 1 and Apple Watch (1st generation) have a water resistance rating of IPX7 under IEC standard 60529. Apple Watch Series 2 and newer have a water resistance rating of 50 meters under ISO standard 22810:2010. Classic Buckle, Leather Loop, Modern Buckle, Milanese, and Link Bracelet Bands aren't water resistant.

https://support.apple.com/HT205000

It will be fine in the water, but will be wet and need to dry once you are out of the water, I would also guess it will fade in a pool with chlorine in the water.

The Silicone Solo Loop may be a better choice for you for Swimming.

Note that it says nothing about showering. Also read your warranty and make note that it does not cover water damage.

waterproof and water resistant are not the same thing and the water resistance fades over time.

The strap is a nylon type fabric and will take some time to dry on your wrist if it's wet.

And the Apple Watch is not waterproof.