I found it in several locations within Bodega Harbor. Most of the time it was a little too distant for my camera lens, but I thought it would still be fun to share a few photos for the record.
Two pictures of the skimmer sitting on the mudflats (in the second image, the bird has its bill tucked underneath its feathers):
Two pictures in flight:
One highlighting the long wings and tail pattern:
And one picture of the skimmer skimming (below). Black Skimmers are named after their distinctive feeding behavior. They don't plunge dive like terns. Instead, the skimmer drops its lower mandible into the water and skims along at the surface trying to make contact with small fish. (Note that the skimmer's lower mandible is much longer than the upper mandible.)
Although there have been several Black Skimmer sightings in Bodega Harbor during the last decade or so, this is the first I've seen locally. The wind was calm enough today that at times you could hear the skimmer calling. Fun!
P.S. If you decide to try to find this bird, the easiest place to see it today was on the harbor side of Doran Beach, near the Rich Stallcup Viewing Platform (opposite the Cypress Day Use parking lot).