I beleive the rule book is the ultimate source for the rules. Secondary is the appeals book which I have seen an appeal overturned but only once.

Anything else is just informed sources. I try to look at who the writer was. The articles in Sailing World by Dick Rose I've seen brought into a protest room as a source of information. I'd say Dick Rose is pretty much the ultimate source for rules opinions. But even he says that his is just an opinion in his explanations and that you have to get a formal ruling following rule 70.3 in App. F.

I've learned quite a bit about 16.2. I haven't read the rules in a few years and this rule has seen some changes. I don't see why it wouldn't apply to boats downwind either reading the rule. But I do believe they both have to be upwind or downwind. Monohulls don't have the issues we have downwind with hunting so I don't think they see it applying there.

I do think that if I was bound by 16.2 I would have been in the wrong by my initial turn down. However I don't believe that boats coming directly at eachother are bound by 16.2. I think it was really designed for the mono's coming upwind hunting eachother.

Here's some more info: Sailing World Rules

Mike Hill