A very successful observation session from San Francisco State University campus! A rainy night and cloudy morning turned to bright Sun just in time for the transit. Not a cloud would be seen for the rest of the day.
I watched the first 45 minutes from home, then brought my telescope down to campus to join three other telescopes set up there. There were hundreds (someone said 1500) people over the course of the 5 hour transit who got a chance to see Mercury's sillouhette on the face of Sol.
Some were disappointed: "Oh, that's all?". Others: "Wow! that's so cool!"
Mercury entered Sol's disk near a large sunspot that is probably 3 times larger than Earth. Mercury's small disk marched across the face of the Sun over the next 5 hours, passing near two small sunspots before leaving the solar disk.