My one negative water experience was during swimming lessons at the Y as a small child. I was probably five or six. We were holding onto the side of the pool as the instructor was talking and I lost my grip and slipped under. The teacher never noticed and I had to grab onto one of the other kids to find the surface. I never went back to that class.
But I did learn to swim when I was 8 at a friend's house. My friend and her sister stood on each a side of the pool where it was just over my head and made me practice swimming back and forth between them. It was fun and I gained confidence enough to later take a Water Safety Instructor class.
My mom is terrified of water, but she insisted my sister and I know how to swim. We have done the same with our children.
One more story - about the impulsiveness of kids at pools.
When my son was 6, we spent a month with my now husband at his apartment, which had a pool. At the pool was a cute, blond, female lifeguard and my son took a liking to her right away.
One morning, about halfway through our visit, we couldn't find my son's floaties (water wings), so we talked about him staying in the shallow water or using the pool floats. He agreed. Well, when we got to the pool, he looked at the little life guard and shouted, "Hey, watch this!" He then ran and launched himself into the deepest part of the pool.
At first I was frozen with shock, but then I took off after him. By the time I got to him, he was back to the surface and holding onto the side with a huge grin on his face. No matter that my heart needed restarting! Since then, he hasn't needed floats of any kind and swims like he was born in water. But it scared the **** out of me!