Our neighborhood pool used to have "adult swim" for about ten minutes each hour, but this year they have not been doing it and I really miss it as a mom of two not-very-good swimmers (my oldest can swim, and touch the bottom in the deeper parts, so he is much less stressful). Making the kids get out of the pool for ten minutes because mom's eyes and neck need a break from the constant watching is much more difficult than having them get out because the lifeguard blew the whistle.
And we used to leave "at the next break" also.
OT - but my "well, I guess it is official, I am a grown-up" moment came during an adult swim. I was pregnant with #1 when the pool whistle blew and the pool emptied of all the children, leaving just me, alone in the pool. I realized that with a college degree, house, mortgage, 401(K), job, husband, and baby-on-the-way, I was definitely an adult. No denying it!