🔍 Key Concepts
• IALA Maritime Buoyage System A used in the North Sea area
• Cardinal marks and how their light rhythms (quick flashing groups) indicate the safe-water side (N, E, S, W)
• How the topmark triangles’ orientation (points up or down, towards or away from each other) corresponds to the cardinal direction
💭 Think About
• First decide which cardinal mark (N, E, S, or W) shows a quick white light with 6 flashes followed by 1 long flash in a 15-second period. Which direction does that indicate?
• Once you know the cardinal direction, recall the standard triangle pattern for that direction (think of the triangles as forming a rough “shape” of the compass side: top heavy, bottom heavy, or like a wineglass/hourglass).
• Compare that mental image to each of the four topmarks (A–D): Which one best matches the standard topmark arrangement for that cardinal direction?
✅ Before You Answer
• Verify from your buoyage notes which light characteristic matches each cardinal mark (e.g., 3, 6+1, 9 quick flashes, or continuous quick).
• Confirm how the triangles are oriented for each cardinal: North (both up), South (both down), East (points away), West (points toward each other).
• Before choosing, double-check that the chosen letter’s triangles exactly match the orientation for the cardinal mark whose light is Q(6) + LFl in 15s.