In my experience the YMCA used young college students to teach swimming to adults. As a beginning I was forced to swim and dive into deep water without preparation and I nearly panicked. In later years the local Y showed favor for people who could learn to swim and abused or ignored those who could not. I later dealt with an authoritarian aquatic director who made it plain he didn't like me after which I got out of there as fast as I could, I lost interest in swimming and never came back. Sure, that YMCA welcomed people it liked. It also drove away people it didn't.