Arctic Loon?? Nope. Common Murre

It seems everyone except me knew that this colorful bird was a winter plumaged Common Murre. It looks nothing like the penguin look-alikes I see in the summer massed atop rocks. But I will forever now recognize it ... (hopefully)

Below was written B.E. (Before Enlightenment)

Help! This bird was swimming with surfers today at Cape Kiwanda. Very colorful, whatever it is.

You can see how close it was to the surfers here. Almost seemed to be deliberately swimming toward and near them.

Here it is blown up (and blurry).

It looks like a loon to me and with all that white on the flanks, an Arctic Loon. But is all the other white here and there because it's in the middle of a molt? Or is it something else?