Update: For comparison, here's a photo I took about two weeks ago of an American submarine cruising off Cabrillo Point, San Diego. In my picture you can see sailors standing on top of the sub as it comes into harbor. Interesting that there are no sailors standing on the Russian sub, especially since it seems like a nice day when the photo was taken.
Update: Stone (in the comments) found a Russian site with more pictures of this sub at the beach, which leads me to conclude that the picture is real because it's unlikely that someone faked an entire series of pictures. According to the machine translation of the Russian site, the pictures were taken at Severodvinsk on the White Sea.