Teach your kids how to swim when they are young. Get them swimming lessons too. At some point, everyone ends up in the water over their heads and if they can't swim, they will panic and drown! So sad, but humans have no instinct to swim like other mammals.
My second wife couldn't swim. And like most adults she did not want to admit it. Well there we were (still in the dating phase) out on the lake in my newly purchased boat. I was fixing to jump in and asked her if she was gonna take a dip. She said yes but something seemed off. She was hesitant. So I out right asked her if she could swim. She said a little. I offered her a life vest which she accepted. She jumped in and came up in almost a panic. I calmed her down. She realized she wasn't sinking and had a great time. I asked her later the same question "Can you swim?" She replied no. She would have sunk like a rock and drowned that day if I hadn't insisted she put on that vest. She never did learn to swim but she had no problem putting on a vest and enjoying the water.