I hate to admit it but this is the fist time I've ever heard that theory. I did think when that teacher said it in Angie's that she was being ridiculous.
You can look it up but I don't believe it's a reason they definitely find it harder learning to swim, I think it's just a theory. But another theory could be minority groups don't always have the same privilege as other groups and a block of swimming lessons at school simply isn't enough, some kids are more privileged and get to practice those skills outside school, holidays, swimming baths. Some kids just don't.
Either way that's not the reason pools were race segregated.
But when she said well they are just left in the little pool, that was wild. Because I was the kid left in the little pool, when I couldn't get the hang of swimming mostly sensory issues I was left with flaoties to do about with no real encouragement.