A Sea of Holes

This was a while back. It's one of the pictures I selected for my Inverness: River and Canal exhibition which never got off the ground. (Apparently you have to be a community group to access the museum's community spaces. Fair enough.) It's on the breakwater which lies on the seaward side of the sea lock at the end of the canal at Clachnaharry.  (Phew!)
Beatles (Yellow Submarine) fans will clock the title.