This Long-billed Curlew was feeding on the tidal flats in Bodega Harbor (close to Doran Beach) on 21 April 2013.
She often plunged her entire bill and head below the surface of the water. (Females have longer bills than males, and this was a very long bill, so I'm guessing it was a female.)
A distant shot, and not quite in focus, but you can still appreciate the slightly different shapes of the upper and lower mandibles.
When identifying shorebirds at a distance, scale is important, and it's often useful to compare known species to each other to get a feel for relative size. In the image below, the Long-billed Curlew is pictured with three other species. (To give you a chance to identify them yourself, I'll wait until after the photo.)
One Marbled Godwit to the left side of the curlew, two Short-billed Dowitchers standing together at the lower left , and one Dunlin to the far right.
For more photos and a little more information about Long-billed Curlews, see the post from 15 January 2012.