🔍 Key Concepts

• U.S. Aids to Navigation System on the Western Rivers (IALA-B in the U.S.) • How mile markers (AHP – Above Head of Passes) relate to charted daymarks • Standard color–shape patterns for river daymarks on the right and left descending banks

💭 Think About

• Ask yourself: On the Western Rivers, when you are going downbound with the current, which side has odd-numbered aids and what color/shape are they? • Think about what type of mark (lateral aid) a dayboard at a specific river mile usually represents and how that’s shown on the chart or river atlas. • Consider whether Togo Island at that mile is on the right descending bank or left descending bank, and how that affects both color and shape.

✅ Before You Answer

• Verify the Western Rivers lateral system: which color/shape corresponds to right vs. left descending bank marks. • Check how red vs. green daymarks are normally paired with triangle vs. square shapes in U.S. inland waters. • Confirm, from a river chart or atlas, which side of the river Togo Island daymark at mile 414.6 AHP lies on before matching it to the color/shape pair.