Towards the end of our day at Moss Landing, CA, we came across another photographer, Efren Adalem, a friendly guy with a big lens who was busy shooting something good.  With his huge lens and tripod, he was getting much better shots than I ever will with my set-up (a Canon 7D with a fixed 400mm lens, handheld.)  You can see his awesome photos on his website.   He told us that the loon he was photographing was a Pacific Loon, a life bird for my husband and I.   It posed and preened for us fairly close by, to our delight!  I got some good photos as you can see, but a local birder pointed out that this is not a Pacific, which would have a clean demarcation of dark and light along its neck.  No life bird for us! And I’m sure the other photographer figured it out as well, that this was “just” a Common Loon.