Actively supervise your children around water and have a phone nearby to call for help in an emergency. Parents often read magazines, talk on the phone or to other adults nearby when kids are in the water, but make sure there's at least one adult paying full attention to the children swimming.
Designate a "water watcher" '- the person responsible at that time for watching children in the water. That adult should give undivided attention to the children in the water and not leave this responsibility without finding another adult to take over. Safe Kids Worldwide offers free water watcher cards (to be held by the adult in charge) for download at SafeKids.org. Ideally, the water watcher card should be handed off every 10 to 20 minutes to keep each adult's eyes fresh for observing.
Make sure your pool has fencing around all sides and a self-closing, self-latching gate to prevent a child from wandering into the pool area unsupervised. Hot tubs should be covered and locked when not in use.
Install a door alarm, a window alarm or both on the side of the house facing the pool or hot tub to alert you if a child wanders into the pool or hot tub area unsupervised.
To learn more about keeping your kids safe around water, visit safekids.org.