Learn to Swim!
It never ceases to amaze me that when living so close to large bodies of water like I do that there are people who don't learn to swim! We have had quite a few people drowning lately who didn't know how to swim, more so that in previous years past. Teach your kids to swim it could possible save his or her life or at the very least if you can't swim use a lifejacket. Its just so senseless to see these people drowning when a few simple swimming lesson could save a life.
Furthermore even if your kids know how to swim PLEASE keep an eye on them, some of these kids that have drown have done so after being swept under a big wave or get dragged under by a current.
I did drown when I was a kid about 8 or 9 I was a very good swimmer at the time (was on a swim team), a wave just happened to hit me before I could brace myself, in the surprise I inhaled some water. Luckily for me mom saw what happened and was able to get to me before I was swept away. I wasn't breathing, thank good she got to me and then had wits enough to perform mouth to mouth. What happened to me happen in a split second, I would be dead now if my family weren't watching us closely (this happened at a family picnic and other family members did rush to my aid Mom happened to be the closest). I mention this because the most recent drowning happened to a six year who could not swim and was left unsupervised by his parents, had someone been keeping an eye on him he'd still be alive today. If I remember correctly the paper said that an hour had passed before anyone realized he was missing. Senseless, a life was lost due to carelessness, poor kid!