The American Academy of Pediatrics (AAP) feels strongly that parents should never—even for a moment—leave children alone near open bodies of water, such as lakes or swimming pools, nor near water in homes (bathtubs, spas).
For backyard pools, rigid, motorized pool covers are not a substitute for four-sided fencing, since pool covers are not likely to be used appropriately and consistently. Parents should learn CPR and keep a telephone and emergency equipment (i.e., life preservers) at poolside.