Power meets sail
Different vessel responsibilities. Foundation level, about 3 min. COLREGs Rule 18.
The situation
You are under power. A sailing vessel, using sails only, crosses from your port side. This is open water, outside a narrow channel or traffic separation scheme, and you are not overtaking.
Which vessel should keep out of the way?
- Keep clear of the sailing vessel: Reduce speed and let her cross ahead.
- Maintain course and speed: Treat the vessel on your port side as give-way.
- Turn toward the sailing vessel: Move across her approaching route.
Lookout: Identify the vessel’s operating state. A sailing hull using machinery is a power-driven vessel for these rules.
The sound answer
Keep clear of the sailing vessel
In the stated circumstances, a power-driven vessel underway keeps out of the way of a sailing vessel. Slowing is an authored illustration of keeping clear; continue to monitor the situation.
Why the other options fall short
Maintain course and speed
Rule 15 concerns two power-driven vessels. Here the other vessel is sailing, and the stated conditions allow Rule 18’s power-driven vessel responsibility to apply.
Turn toward the sailing vessel
Your duty is to keep clear. In this geometry, turning toward the approaching sailing vessel does not provide the clear separation illustrated by slowing.
Rule 18 · Responsibilities between vessels
Subject to the exceptions in Rules 9, 10 and 13, a power-driven vessel underway keeps out of the way of a sailing vessel. The operating state and context matter.