We see them fairly regularly up here in Northern Mo Co... I've seen them on the beach, on the rocks, in the Shrewsbury river... but mostly just fishing just outside the surf zone. Mostly Harbor seals, but once in a while a Grey seal. You can tell them apart by the shape of their heads... Greys have really long, straight, pointy heads, and Harbors have smaller heads with shorter noses. You can't go by color, because both come in different colors. Greys are bigger, too... but most of the time you only see their heads popping up.
One time I was out in Deal, early spring, nobody out.... and I'm sitting there on my board. Out of the corner of my eye, I see something pop up right next to me and at the same time hear this big sort of "snort".... actually, it was exhaling and blowing out water from it's nose. Scared the crap out of me. When I turned my head really quickly to see what it was, I kinda went, "whoa!" and then he did the same thing... he had come up right next to me, but facing the other way, so when I said, "whoa!" I startled him, too. He snapped his head around, looked at me with a big, round, dark, glassy eye, and in less than a half a second slipped right back under water without a splash.
i saw one beached this fall. It was alive but obviously hurt and must have been pounded by the surf. Rescue center came and picked it up. Poor little guy. They look like dogs with flippers.
I also saw one cruising in the back bay while I was fishing. I thought it was a dog at first. When it noticed me it dove under and disappeared.