In Florida we teach the kids to swim as soon as they can walk.
Way to much open water here
My wife taught swimming most of her life as a certified instructor. She taught the instructors how to teach swimming. As our friends and neighbors were having kids she would go to their homes and teach “drown proofing” to the kids starting around 6 months. If they didn’t have a pool or it was too cold she would use a bathtub.