COLREG Rule 15 — Crossing
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.
In practice
Give-way vessel alters course substantially to starboard or reduces speed. Small alterations breach Rule 8.
Regulatory detail & full definition
COLREG Rule 15 — Crossing: '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.' The give-way vessel typically alters course substantially to starboard or reduces speed; small alterations are inadequate (Rule 8). The stand-on vessel maintains course and speed under Rule 17 until it becomes apparent the give-way vessel is not taking appropriate action.
Authoritative source: COLREG 1972 ↗
Related
Source: COLREG 1972 Rule 15
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