1. At the opening of a bridge or weir, the rules of article 6.07 shall apply unless the fairway is wide enough for simultaneous passage.
2. When passage through the opening of a bridge or weir is authorized and the opening is marked by:
(a) The sign A.10 (annex 7),
navigation is prohibited outside the area between the two boards constituting this sign;
(b) The sign D.2 (annex 7),
vessels are recommended to keep within the area between the two boards or lights constituting this sign.