When I was a kid in Florida in elementary school, that’s what most elementary schools did, mine was next door to a swimming pool so we just walked. At the time I think it actually was mandated by the state - swimming pools in backyards are extremely common there and it was an upsettingly common occurrence for kids to drown in them, so they took a week to make sure we all knew how to tread water. I don’t know if Florida kids still learn how to tread water or if swimming lessons are now woke somehow.