Safety covers, both solid and mesh, come in all shapes and sizes but they are (relatively) expensive. Everything SO says helps, and the safety cover adds ANOTHER layer of protection...it can also prevent large branches from tearing a vinyl-sided pool. Kidney-shaped is fairly standard. I have pretty much the same setup as SO, and similar rules. "Adult" supervision ends about when you get a driver's license (my older). The safety mesh (my preference) is my last line of defense. It's never been tested, but, like air bags, you still want them there.