Many parents believe their two-year-old can swim when, in reality, their child isn't actually swimming. Just because a small child may be able to move in the water doesn't mean he is consciously keeping himself afloat. Moving in the water is an instinct for some babies, but paddling is not the same as swimming — and does not guarantee that a child's head will stay above water.

A child can drown in a moment even in very shallow water because he can't always pick up his head if he should fall. Or he could panic and not remember to pick up his head. An adult — not an older child — needs to be in the water accompanying a two-year-old at all times. This rule applies not only to pools, but to any body of shallow water, whether the ocean's edge, a lake, a toddler pool, or a bathtub.

Pools should be covered and fenced off, and motion detectors and sensors, in case small children go in or fall in when no one is looking. These sensors are available at hardware stores, pool-supply stores, and Web sites that sell child-safety equipment, such as www.childsafetystore.com.

Many two-year-olds enjoy playing in kiddie pools, which are small plastic pools you can buy at most pool and toy stores and that you fill with a garden hose. Do not leave your child unattended near a kiddie pool. Have him wear water wings in the pool if he wants to try to swim or float. Always empty the pools when you're not using them. That way your child can't happen to wander over to it and fall in while you are distracted, and you won't be leaving the pool to fill with dirty water. (Chlorine for killing germs is not used in kiddie-pool water.)