Summer Sailing!

Haven't been posting things for a while. We've been busy sailing Constance around the SF Bay.  Weekends are a huge relief from daily job pressure and other ordinary things, so we usually stay at least every 2nd weekend on the boat. Summer is the time to go sailing here! The thermals set in around noon and increase from a benign 10-15kn all the way to 30-40kn on a hot summer day. Which can be quite cold in San Francisco, by the way. What's causing the thermal wind is really the temperature difference between the California Central Valley and the Coast. Over a distance of 100 miles the temperature difference can be as high as 40 degree Fahrenheit or 20 degree Celsius. The hot air rises over the Central Valley and pulls in cold air from the ocean. Hence the fog you often see in the summer in San Francisco. The air has to funnel in between Peninsula of SF and the Marin Headlands in the North, creating an accelerated flow of air roughly between the City Front and Alcatraz Island. That area is also called "The Slot", where the highest wind speeds can be reached. The 34th America's Cup in 2013 happened exactly here for a reason!  Below a video from one of those days, early afternoon just south of Alcatraz, winds peaking around 25-30kn. No problem for Constance with the first reef tucked in!