Feel free to chime in on what the temp is of the water on your lake or river. I'll start...
This is the reading in the channel taken from the water temperature gauge on my supra so it may not be 100% accurate. All I know is it's still pretty dang chilly for the heater top, but that isn't stopping us. This is taken on Fort Loudon lake in Knoxville, TN near the Pellisippi Parkway Bridge