I started out from the Dolphins Swimming club at Aquatic Park. I swam along the half mile course marked by buoys inside the sea walls.
I had views of Alcatraz, but only glimpses of the Golden Gate Bridge through the fog. Foghorns were sounding out continuously across the bay.
There was no temperature chalked up on the board, but I reckon it was about 15°C, so I was glad of the hot shower and sauna in the clubhouse afterwards.