Okay, I finally got in open water today.
I was visiting a friend who is letting us have an old kayak, and was talking about conditioning myself to swimming in cold water, and mentioned that I was planning to do a cold water swim this weekend. A short one, obviously. I might be crazy, but I don't want to hurt myself.
She lives on a small river and we are of a size. She asked me if I wanted to borrow a bathing suit and we'd go for what she calls a Spring Scream. (You jump in cold water and you scream)
My best estimate, from checking on fishing reports of local lakes and taking into account that a shallow, but flowing river is probably a little cooler, is that the temperature was about about 50F (10C), give or take a degree.
The day was unseasonably warm for Vermont, and there was little wind, so I agreed to go for it. I got in three times, swimming a few yards (breaststroke) each time and getting out -- just to acclimate myself and test how I could handle it.
Was it cold?
My word yes!
What it wasn't was miserable. I'd been turning the showers to cold occasionally and sticking my hands in cold water all winter trying to brace myself. Instead of acclimating myself, I think I was psyching myself out for it to be awful.
It wasn't awful. It was exhilarating!
It was also comforting. My open water swim is in a month and the lake is going to be a lot warmer than the water I was in today. I freely admit I'd been scared of how cold it might be.
Not so much. I was worried it was going to be awful rather than exciting.