As the weather is warming, people are wanting to cool off. That's cool, and if there are more options than wearing wet clothes and soaking one's head or feet in some cold refreshing water, why not enjoy some time swimming in a safe, supervised area.
But when it comes to diving or doing flips and stunts off the edge of a cement pool or any surface you could slip (especially rocks) Think Twice. If there's signage prohibiting such things by the town or landlord of a spot, then heed that.