🔍 Key Concepts

• Lateral aids on the Mississippi River and how red aids are shaped for upstream travel • Difference between lights and daymarks on fixed aids • How chart symbols show the shape and color of dayboards/daymarks

💭 Think About

• Think about whether you are considered to be going upstream or downstream at mile 335.4 AHP and how that affects the shape of red aids on your right side • Recall what standard shape is used for red lateral marks (vs green) and whether that shape changes when used as a daymark on a light structure • Consider whether a federal lighted aid on an inland river would typically be shown with no daymark, or with a specific standard dayboard shape

✅ Before You Answer

• Check the Inland River buoyage system convention: what shape corresponds to red aids on the right when proceeding upstream • Verify on a sample chart legend how red daymarks are depicted (square, triangle, diamond, or none) • Confirm whether a named light like Joe Pierce Light is a federal aid with a standard daymark or a private aid that may lack a daymark