My experience with Aussie registration
(2 boats in the 30 ft range) is that they are sensible when it comes to the marking aspects (strange I know
). The rules are written for shipping
so can't always be complied with to the letter of the law for yachts.
What you do need to comply with is the intent (or spirit) of the rules. The marking has to permanently attached to the vessel, easily readable and located in an obvious position.
I have used a engraved stainless steel
plate (about 6" x 4") with 1" lettering and screwed / glued on the first main bulkhead in the saloon
. The screw heads were ground back to remove the slot - sort like a rivet in appearance.
Everyone (?) seemed perfectly OK with the marking but the truth be told, only the guy signing the marking compliance ever cares about it. Customs
just glanced at it when leaving/arriving etc.