Stuck tight and out of sight.
I have a Passage 450 and I had a teak board prepared with 3 inch high numbers as required.I epoxied the board to the structural cross member inside the compartment, below the sole, that contains the seacocks for the engine intake and seawater intake for the mid-cabin head.I also used a permanent marker to write the number UNDER the board just in case it were pried loose or off for any reason.After it cured I epoxied the entire surface area of the documentation board.I was also going to epoxy it to the bulkhead inside the lazzeretes.It is supposed to be engraved or attached permanently to a structural member.