Yesterday morning the water temperature was 55F (13C) and the air temperature was 36F (2C). We are having a cold week, so the temperature of the water is finally dropping towards winter conditions.
What was new to me is the heavy fog that was over the lake. The warm water and cold air were ideal conditions for this. The other swimmer is very experienced and was quite fearful of the fog. With no wind or waves, all directional ques are lost once you get into the fog. Even though our swimming seems fairly straight, this is only because we have visuals to help us correct course every few dozen yards. The solution was to swim along the shore, which we did without any mishaps.