Get your boat registered by post for the lake before you go and then you can make up some boards to put the bl***y great numbers on which make an acceptable way of displaying them in a temporary way instead of sticking them on the boat. And dont forget to display them. I teach for an O.E.C. up there from time to time and also did the instructor course for the wardens there and spent some time on their rib and Draco enforcement boats. Onboard computer sends and receives details of who and what the numbers relate to, previous warnings etc, whilst they are looking or talking to you. via mobile phone modem. Nice guys though as long as you talk to them properly and grovel if you are in the wrong!! Remember you must have a competent observer and a rear view mirror if towing a skier. There are several speed limit areas and limits are rigorously enforced. Also a number of propeller eating shallow areas particularly south of the chain ferry which are buoyed off. You can get a free map of the lake from the wardens office. Couple of free mooring piers up a couple of miles north of Bowness at "Miller Ground" where you can land and do the barbecue.
Shame about the speed limit. I will miss the shock when I fall off the ski (regularly) and find that the water isn't salty.