1. In order to avoid so far as possible meetings on sections or at points where the fairway is not unquestionably wide enough for vessels to pass (narrow fairways), the following rules shall apply:
(a) All vessels shall proceed through narrow fairways as quickly as possible;
(b) Where the view is restricted, vessels shall sound one long blast before entering a narrow fairway; if necessary, especially when the narrow fairway is long, they shall repeat this signal while passing through it;
(c) On waterways for which “downstream” and “upstream” are defined:
(i) A vessel or convoy proceeding upstream, on becoming aware that a vessel proceeding downstream is about to enter a narrow fairway, shall stop below the fairway until the vessel proceeding downstream has passed through it;
(ii) When a convoy or a vessel proceeding upstream has already entered a narrow fairway, vessels or convoys proceeding downstream shall, so far as possible, stop above the fairway until the convoy or vessel has passed through it;
(d) On waterways for which “downstream” and “upstream” are not defined:
(i) Vessels having no obstacle to starboard and those which in a curved narrow fairway have the outside of the curve to starboard shall hold their course and other vessels shall wait until they have passed through the narrow fairway; however, this provision shall not apply to small craft in relation to other vessels;
(ii) In the case of a meeting between a small craft under sail and a small craft of another category, the small craft under sail shall maintain its course and the other shall wait until the small craft under sail has passed through the narrow fairway;
(iii) In the case of two sailing vessels meeting, the vessel to windward or, if both are navigating with the wind, the vessel which has the wind on the starboard side shall maintain its course and the other vessel shall wait until it has passed through the narrow fairway.
This provision shall not apply to small sailing craft in relation to other vessels.
2. When a meeting in a narrow fairway has become inevitable, the vessels concerned shall take every possible precaution to ensure that they pass at a point and under conditions involving the minimum danger.