Kate, the water temperature is fine for shortish non-wetsuit swims although having said that, I made a navigational error last night (aimed for the wrong buoy) and added about 10 minutes to my planned 20 minute swim.
Had blue hands and uncontrollable shivering afterwards so definitely stayed in too long!
On the plus side the water is incredibly clear and free of weeds/duck shit!
My son's training for Ironman Muskoka so he's using the lake for long (wetsuited) training swims. We have a DIY sprint tri that we do over there once a week. Feel free to join us on Sunday if you want.
Have been mostly SOC swimming of late at Frensham but was out for a run this morning albeit one that was interrupted by several stops to chat to dog walkers. Will be back in the lake this evening for a swim and then again tomorrow morning with the FARTS!