🔍 Key Concepts

• Intracoastal Waterway (ICW) aids and how they differ from standard lateral marks • Meaning of a dual-purpose marking in the U.S. Aids to Navigation System • How yellow markings are used on buoys and daybeacons along the ICW

💭 Think About

• Think about what extra feature is added to an aid when it needs to serve BOTH the regular lateral system and the ICW at the same time. • Ask yourself: when you see a standard red or green buoy that ALSO serves the ICW, what specific part of its appearance tells you the ICW direction? • Consider whether ICW guidance depends more on overall color and shape, or on a smaller, specially colored marking added for ICW use.

✅ Before You Answer

• Review how yellow symbols/marks are used on buoys in the ICW (e.g., triangles, squares, bands, or small marks). • Confirm whether ICW direction is determined by the overall lateral color/shape or by an additional colored feature on the aid. • Make sure you know the difference between using an aid’s main body/shape versus using a small added marking to interpret ICW information.