I just now dug this one out and took this picture. I had to look all over to find where I put it.
I found it a few years ago down in the Outer Banks, with my Fisher CZ-70. I was actually hunting the base of an old shipwreck keel that's visible on the beach near Corolla. I found it about 8" down and from the signal, I figured it was quarter-sized. I about dropped a load in my pants when I saw it, until I turned it over and saw "Copy". Man, was I disappointed. I looked around to see if I was being punked but there was nobody else in sight. When I hit the convenience store on my way home right after I left the beach there was a little container full of them at the checkout...$1.99 each.
Looks to be the same as your to me...mine's just in better shape.