Cartop Cat?

Thanks Dennis, it looks like I'll have to take a good look at the way we're set-up. In the UK I know that I can get a red/white striped triangle, but are you saying it needs to be a 50x50 square? Is the illumination white or red?

Cheshire, I don't know how they're classified, but I got pulled near home on my way back from Datchet last year and all was OK.

It's definitely a square (I believe one is mandatory in France and Belgium also)! Lights are only needed if driving at night, and to be honest I've never actually seen one with lights on a boat before... If you get one with lights the forward facing light needs to be white, the rear facing light needs to be red.

Dennis