Given a RC boat which is both an obstruction and a mark, and assuming section C is in effect. Is it correct to say that the only rules that apply from Section C at the RC boat are 18 and 20?
Interpretation: Because the RC boat is both an obstruction and a mark, 18, 19 and 20 from section C would apply. Except that, 19 stipulates that it does not apply "when the obstruction is a mark the boats are required to leave on the same side". So that would only leave 18 and 20?