It was cut from small trees, judging by the number of knots, and seems to be quite plentiful. Our beach faces the other way here, but I have seen pretty good cedar in small quantities on beaches in Washington and Oregon. It's mostly red cedar in this case.
Yellow cedar is very expensive and difficult to get out east.
Mainly because it has to be cut from Canada where there are reletively few left. I met a guy who claimed to use fallen and beached yellow cedar but that claim turned out to be false for the most part. There just aren't enough of these Grandfather trees for us to play with any more.