Thanks Brett, I see what your original question is now…
One rule says the boat (per ISAF) has to be in the box, and another provides a slot (for a rudder which probably cann’t fit in the box) so you can have a rudder that doesn’t fit in the box.
So for this class, we must amend the definition of boat so that it means, in this case, the hull and keel, and then the rudder can either fit into the box somehow, or through the slot, with the limits specified there. And possibly change or add a rudder rule to specify if it can be turned, or must be straight, either in the box or in the slot.
I think this will be animportant point, because, as the design of the Footy is unexplored, to the point of what an efficient hull & rudder arrangement is, we need away to allow the different arrangements to fit into the rule.