Semipalmated Sandpiper

I've been staring at these pictures for some time since I took them last Friday at Coburg Peninsula during our trip to Victoria. I've been trying to convince myself that the bird is a Semipalmated Sandpiper and not a Western Sandpiper, but I am not very experienced with Western Sandpipers and have never identified a Semipalimated Sandpiper.
They have been commonly reported on OBOL recently so I have been hoping to see one. Trouble is, they look almost identical to Western Sandpipers. The biggest difference is the bill. Westerns have a longer bill that droops down a little at the tip. Semipalmated's bill is shorter and not as drooped. Semis also have a grayer, less rufous back than Westerns, but with the variations of coloring within each species, they kind of blend together.
It took quite some time before I started getting more confident on the identification. Then I got the idea to try a Yellowlegs identification technique and compared the length of the bill to the length of the head. Sure enough, the bill on this bird is clearly proportionally shorter than its head compared to the bill/head proportion of Western Sandpipers. So, I'm now about 99% sure of the ID.
I found three of these Sandpipers together on the harbor side of Coburg Peninsula. They were on a small mudflat and had enough trust to let me get in close. As a matter fact, the top picture is of one walking right past me as I was kneeling on the beach. All three scooted right past me. I practically screwed myself into the sand as I followed them with my camera. :-)