When my eldest dd was 2, I watched her almost drown. It absolutely was quiet. ANd her dad was literally standing in shallow water a foot or two from her !
I was 8 months pregnant with our second, we were on a retreat "camping" trip with alot of extended family, his siblings with their spouses and children. Our child was the youngest. A few of the fathers were in the swimming hole with the kids, my husband had our 2 year old. I was far back on beach with other moms, supposed to be relaxing and reading magazines, etc... I happened to be looking that way because it was nice to see them all playing. He was right there with her, but shallow water for him was high up on her chest. He turned the other way to talk to his brother and watch the antics of the older kids, she took a step, and then was just silently floating face down in the water. no noise, no movement. It was very surreal. No one else saw it but me, I wasnt close. The guys in the water are just talking and laughing. I started yelling and moving, it was real crowded, so this sea of people is parting for me - the crazed, huge whale of a pregnant woman yelling, gesticulating and lumbering towards the water. About the time my feet hit the water, he heard me, looked back and pulled her out, sputtering and coughing up water. Once I saw she was ok, I smiled (at her only) and walked off, I didnt want her to become scared of the water. But, it is that quick. In a crowded vacation spot, she could easily be unnoticed long enough to need medical attention, brain damage from oxygen deprivation, or die, and all silently. My husband could never admit she was in danger, or there was a problem, which was actually the scariest part of the whole thing. Other fathers I didnt know who witnessed it at the swimming hole did come up to me during the week, they got it, and it realy made them keep an extra eye on the little ones. One told me, that he thought at the time, "I'm glad that wasnt me..."
I never took my eyes off of her the rest of the week, and she did have so many swimming lessons and was such a water kid that she swam on swim team for college