It was a pretty sharp 11.9 degrees in Guildford Lido today, I managed a good swim but was properly frozen afterwards compared to last week even though it was less than a 1 degree drop.
It’s utterly exhilarating getting out at the end, but knowing the fine line between enough and too much is a delicate act. I carefully monitored myself and avoided any signs of early hypothermia however.
But I still haven’t managed to satisfy myself if it’s possible or not to, say, swim a mile outdoors in Surrey in the middle of Jan / Feb without serious repercussions. If so, I’d be sincerely tempted to not buy a wetsuit…
Perhaps taking the wetsuit off at the end of a training swim for a few laps in skins might be the way to go in mid winter.
Ask any project manager about the key to their success, and they will say that delivering a project is often more like a "dark art" or by chance, than a predictable science.