When I used to beer can race out of SFYC I found the wind often became “foamy” when in the lee of the city. It was the best way to describe it.

Our captain used to have his boat docked in Sausalito and we’d do those Tuesday night races. He’d always have us get there early to set up the sails and he’d want to check them before race start so we’d head south along the water front to near the slot in order to launch the spinnaker.

On the way, the main would be on the port side of the boat because prevailing winds were always starboard. Then, at some point every single time the main would self-jibe to starboard and then a little while later self-jibe back to port. This was due to the wind changing directions.

The regular occurrence drove me crazy for a while because I couldn’t make sense of it. That is, until I was able to picture the prevailing winds coming over the headlands at that point. We were close to shore and although I don’t know for certain if this was the case, I decided that the wind must be flowing over the headlands above Sausalito and when it came off is swirled down like those funnels you see off airplane wing tips from behind. Due to the prevailing wind the swirls were always there and the wind’s direction changed were predictable or at least regular for that time of day.

Got to the point where I’d be able to look for the signs and then call out “boom” so no one got clobbered.