I guess I am suggesting that at least some of the rock art boats are wooden hulled.
These boats even have the suggestion of a mast
http://www.megalithic.co.uk/modules.php?op=modload&name=a312&file=index&do=showpic&gid=309&pid=15946&orderby=dateD
I have never seen a picture of an actual skin-hulled boat with a high prow and stern post .