Icy cold water is different with what happens. Is very possible to slowly wade into 40-degree water wearing just a swim suit and water shoes to install a dock or boat lift.
If you fall out of a boat or something into deep icy water that's over your head it a shocking experience and you have a serious problem if you don't have the flotation of a pfd. I think the sudden shock of the intense cold is a big problem.
Best advice; wear a pfd and keep your mouth shut. When you suddenly get immersed ..... it's like .....omg ...... get me outta this icy cold water asp pdq ..... it becomes intense ...... and causes you to panic.
There are no You-tube videos of actual drownings that really show what happens? .....
Like ..... in this video .....
www.youtube.com/watch?v=nyuRRWC5GY8 ...... with Janna from Sweden, she is actually standing on the bottom of the frozen lake, and not in water over her head ...... go Janna!