The vessel which has the other on her starboard side shall keep out of the way.
Rule 15: Crossing situation
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.
Wording follows the International Regulations as printed in the US Coast Guard Navigation Rules handbook (2024), with British spelling, and is shortened in places. Download the rules
Read the whole of Rule 15 on one page
Rule 15: Crossing situation
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.
Test yourself on Rule 15
Two power-driven vessels are crossing with risk of collision. Which vessel is the give-way vessel?
The vessel which has the other on her own starboard side. Rule 15: the vessel which has the other on her own starboard side keeps out of the way and avoids crossing ahead.
A training aid, not the official text. The COLREGs are an IMO convention, and your national authority publishes the version that applies in its waters. Check the rules themselves before you rely on them at sea. Download the rules.