(e) Whenever the Government concerned shall have determined
that a vessel of special construction or purpose cannot comply fully
with the provisions of any of these Rules with respect to the number,
position, range or arc of visibility of lights or shapes, as well as to the
disposition and characteristics of sound-signalling appliances, such
vessel shall comply with such other provisions in regard to the number,
position, range or arc of visibility of lights or shapes, as well as
to the disposition and characteristics of sound-signalling appliances,
as her Government shall have determined to be the closest possible
compliance with these Rules in respect to that vessel.