I had a sailing test a few weeks ago and in it I was presented with the B flag and was asked what it means and what would be the applicable light at night.
I know the answer is "carrying dangerous substances and the light is an all-round red light" but I can't find where this is defined to make sure I'm not missing other rules not in COLREGs (Collision Regulations).
Are there any additional international rules for boating lights and signals apart from the COLREG Navigation Light and Signal Flag Rules?