BOTH INTERNATIONAL & INLAND In illustration D005RR below, vessel "A", which is pushing ahead, and vessel "B" are crossing. Which is the stand-on vessel?

Correct Answer: Option A — Vessel "B" is the stand-on vessel because she is to starboard of vessel "A".

Under COLREG Rule 15, 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. Vessel B is to starboard of Vessel A, making Vessel B the stand-on vessel.