never too late. it takes much shorter time for a primary student to learn swimming, I meant literally swim not Just breathe and float for several metre. this is because of their better body coordination. my girl literally took only 4 lessons to learn breaststroke when she was 8. vs her little brother took much longer time at 5. however there may be a consideration that some kids are getting more timid at older age.
if kids not reluctant to water playing, no harm to start learning swimming at very small age. But shouldn\'t expect it would be a short course, And it\'s not fair to compare across different kids, some are born with better physically coordination.
to me, learning it at older age save me lot more money.