Rule 15 Crossing Situation
Crossing Situation — International
(a) When two power-driven vessels are crossing so as to involve risk of collision, the vessel which has the other on her own starboard side shall keep out of the way and shall, if the circumstances of the case admit, avoid crossing ahead of the other vessel.
Crossing Situation — Canadian Modification
(b) Notwithstanding paragraph (a), in Canadian waters, a vessel crossing a river shall keep out of the way of a power-driven vessel ascending or descending the river, except on the St. Lawrence River seaward of Île Rouge.