Pool workout

The Apple article does not give a maximum duration. It will depend on the level of charge.

Swim with your Apple Watch - Apple Support

Apple never ever use the term Waterproof.

The SE and Series Watches are water resistant for shallow swimming, the Ultra for shallow diving .

However they are not guaranteed water resistant and if they leak it's tough luck on you.

It's why I never even get mine wet.

PS 50 metre and 100 metre ratings don't mean that you can use them at that depth. It's a world wide Watch industry mythical rating relating to testing routines.

I just gave you the link with the warnings so they demonstrably did warn you.

It is rare for Apple Watch to leak so to have three Watches leak in a row suggests to me some out-of-spec usage. Diving to the bottom of deep end for example? Showering with shampoo?

I assume you didn't get free replacements.

They do

"Water-resistance isn’t a permanent condition and can diminish over time."

About the water-resistance of your Apple Watch – Apple Support

You're most welcome!

replaced 3 watches in 6 months. I swim 1 hour almost everyday.

Is that a good or a bad observation?

Very bad. Apple sells must warn customers that se series not suitable for swimming (instead of replacing it frequently).

They not

I followed all the instructions in the article, problem not solved.