🔍 Key Concepts

• Lateral system of buoyage and how channels are marked near bridges • Special markings used to show the centerline of a navigable span on fixed bridges • Differences between shapes/colors used for regulatory vs navigation/channel marks

💭 Think About

• Think about which choices look like regulatory or warning signs versus those that would help a mariner stay in the center of a span at night • Ask yourself: on a bridge, what kind of simple light or shape would be easiest to line up with from a distance to stay on the channel centerline? • Consider how aids to navigation differ between dayboards/signs and lights, and which is more common for marking the exact center of a span.

✅ Before You Answer

• Identify which options resemble regulatory/information signs (used for rules, exclusion zones, etc.) rather than channel marking • Recall that centerline marks on bridges must be highly visible and usable at night for alignment • Eliminate any shape/color combinations that are typically associated with danger, exclusion, or special information rather than basic channel guidance.