🔍 Key Concepts

• Navigation Rules – Part C: Lights and Shapes for sailing vessels • Required lights for a sailing vessel underway versus optional lights • Size distinction for sailing vessels less than 20 meters in length

💭 Think About

• Think about what the basic "power-driven vessel" light pattern is, and then recall what is different for a vessel under sail only. • Ask yourself: what are the minimum required lights for a sailing vessel of 15 meters at night, and which lights are only optional (extra) to help show she is a sailing vessel? • Consider whether a 15-meter sailboat is allowed to combine some required lights into a single lantern and, if so, where that lantern is mounted.

✅ Before You Answer

• Verify in the Navigation Rules what lights are required (not optional) for a sailing vessel underway less than 20 meters. • Check whether the red over green, "sailing machine" lights are mandatory or optional for a sailboat of this size. • Confirm whether the rules allow combining sidelights and stern light into one lantern on the mast for vessels under a certain length and whether 15 meters falls within that limit.