🔍 Key Concepts

• Preferred-channel lateral buoys and how they differ from primary lateral buoys • The meaning of composite group-flashing (2 + 1) in light characteristics • IALA buoyage: what red and green indicate** on lateral and preferred-channel marks

💭 Think About

• First, recall what a preferred-channel mark is used for and how it is shown on charts and in the Light List—what makes it different from a simple port or starboard lateral mark? • Think about the term composite group-flashing (2 + 1). What does the group of 2 flashes represent, and what does the extra single flash represent? How is that tied to the preferred channel? • Among the choices, which options describe light colors and characteristics normally associated with lateral marks that indicate which side is the main or preferred channel?

✅ Before You Answer

• Verify in your buoyage reference which light characteristic is specified for preferred-channel marks (look specifically for the notation (2 + 1)). • Confirm the color of the light that may be used with preferred-channel buoys and how it relates to the color of the top band on the buoy. • Eliminate any options that describe characteristics normally associated with safe water marks (like Morse (A)) rather than lateral or preferred-channel marks.