I think the gallows/grab rail that is shown on the drawing is an excellent idea, Robin. I have one in a similar place, and it protects that "bad step", as you climb in and out of the cockpit, slightly off-balance.
Enjoy your cruise through the Baltic. I certainly did, when I transited the Gota Canal and wandered through the Aland Archipelago as far as Naantali, in 2004.