Dinghy boarding ladder
I have the same problem. I''ve thought of tying one end of a three or four step ladder to the side of the dink and tying some kind of light flotation to the other. When I want to board the dink, I would swim to the floating end of the ladder and sink it under my weight then climb the ladder. I would lash the ladder to the side of the dink when not in use. Could it work?