Kids naturally want to do the right thing and teaching them to never go near water without a grownup is the very first line of defense in drowning prevention. There will be nothing more important about water safety that you can teach kids. Make sure they know never to go near the water without you for the times you're not there with them.  And when you're the grownup who is with kids by the water, be vigilant, be aware and reaffirm that you're the one responsible for their safety. Before anything else, make sure kids know: Never go near the water without a grownup!