I was planning to secure bridle with a couple of eyes screwed to the underside of the gunnel. However from Matt773’s reply the idea of a slot or a small hole sounds a very simple method of securing a rope with stopper knot.
Certainly knot & hole is the simplest but most often forgotten method of securing things on a dinghy.
I’ll just have to carefully seal the exposed timber grain in the stopper hole to avoid those nasty black water stains on my newly fitted decks.
Peter W3035