🔍 Key Concepts
• Lateral system of buoyage used in the United States (red/right/returning, green, preferred channels, etc.)
• How bridge channel markings indicate the edges of the navigable span vs. the exact centerline
• Standard light colors and groupings used for aids to navigation vs. special-purpose lights
💭 Think About
• Think about what color and pattern would most clearly and consistently show a vessel operator the exact middle of a span—would it look like a single light, a group of lights, or a different color?
• Ask yourself which of these options matches what you would expect to see on many different bridges marking the safe channel center, not just a one-off case.
• Consider what light colors and patterns are commonly used in the lateral system for navigation aids, and which of these answer choices does NOT normally represent a standard lateral mark or special-purpose signal.
✅ Before You Answer
• Verify in your study materials what specific light arrangement (how many lights, and what color) is prescribed for the centerline of a bridge channel.
• Confirm that the color you select is appropriate for safe-water/centerline indication, not for marking just one side of the channel or a special condition.
• Check that the light characteristic (fixed, occulting, flashing, etc.) in the option you are leaning toward matches what is normally used for a constant, always-visible reference like a channel centerline.