Is anyone still swimming open water? I decided to try none wetsuit for as late in the year as possible this winter. Started non wetsuit in the summer and stuck with it. I'm just about hanging on in my swim jammers and single silcone cap. The air temperature makes a big difference. I did 40 min in the water around 10 degrees twice this week but only managed twenty minutes at 5.7 degree water at the weekend with 1 degree air temp and was suffering at the end. It also takes a surprising amount of energy to warm up after. I'm fine swimming then running or cycling normally and have cycled an hour each way to open water swimming in the past. Warming up after a cooler swim takes some effort from your body. Going from a swim to a league XC running race turned out to be a terrible idea .