🔍 Key Concepts

• Lateral system vs non-lateral aids in the U.S. Aids to Navigation System (ATON) • Meaning of red triangles and green squares in the lateral system (Region B in the U.S.) • Purpose of informational / regulatory daymarks (shapes and colors that do NOT mark channel sides)

💭 Think About

• First, decide which of the options are clearly used to mark the left or right side of a channel when returning from sea under the U.S. lateral system. • Then, think about which shape and color combination is commonly seen on signs that give information, warnings, or restrictions rather than marking channel edges. • Ask yourself: which of these marks could appear away from a channel and be used mainly to convey information or warnings, instead of telling you which side of a channel to pass on?

✅ Before You Answer

• Identify which shapes/colors are standard lateral channel markers ("red right returning" and its green counterpart). • Recall that regulatory / information daymarks often use black and white patterns instead of red/green lateral colors. • Confirm which option is most associated with hazard / exclusion / information signs, not with marking the port or starboard side of a channel.