🔍 Key Concepts

• Lateral aids to navigation in the U.S. Aids to Navigation System (red right returning, port vs. starboard marks) • What daymarks on a light structure can indicate besides just side of channel (e.g., ranges, crossings, fairways) • The meaning of pairs of dayboards/daymarks on the same structure—are they usually range markers, channel-side markers, or something else?

💭 Think About

• First, decide whether the daymarks you see would be marking the port or starboard side of the channel when returning from sea. Which color/shape would that be? • Next, think: if there are two daymarks on the same structure, what additional purpose might that serve—are you lining something up, indicating a crossing, or marking mid‑channel? • Ask yourself: does a single structure usually serve as a range (front and rear) or would a range normally consist of two separate structures with different elevations? How does that help eliminate some options?

✅ Before You Answer

• Be clear on the meaning of port-side vs. starboard-side lateral marks when “from seaward” is specified. • Confirm whether a range is typically made up of two separate aids (front and rear) rather than two plates on one structure. • Check how a channel crossing or mid-channel fairway would normally be marked in the U.S. system and whether that would appear as two daymarks on one light.