If you really want your kids to be safe in the swimming pool, keep an eye on them the whole time or better yet get in the water with them.
But sometimes our minds wander or we need to go to the toilet or anything can happen that takes your attention away from your child.
As an extra precaution you could make your kids wear the iSwimband, even the ones that are not supposed to be in the water. It's a safety device that alerts you on your smartphone when it has been submerged for too long, which could mean that your child is drowning.
If your child is a swimmer, the device goes around the head. Toddlers who are not supposed to be in the water should use the non-swimmer version, which goes around the wrist.
$99 when it was on Indiegogo.