Must be getting marginal though?
To be honest, it's been fine so far. Obviously I can tell it's fairly cold but it feels perfectly bearable. I think swimming throughout the autumn really has acclimatised me. That said, I don't understand the idea of acclimatising to cold water. It can't really be physiological, can it. Once you're fully warmed back up does your body really retain some adjustment? Acclimatisation to altitude must induce much more physiological change but even that is lost quite quickly when you come back down. Anyway, I hope to eke out a couple more weeks but expect there'll soon be a tipping point where it gets not bearable at all. But enough for now of my puny efforts.