🔍 Key Concepts

• IALA-A lateral system – colors and shapes for port vs starboard marks • How light characteristics (quick flashing, group flashing, isophase, long flashing) are used to distinguish different types of marks • Difference between simple port lateral marks and preferred channel to starboard marks (Port-hand bifurcation marks)

💭 Think About

• First, recall what color and shape a standard port-hand lateral mark has in the IALA-A system, and what its usual light rhythm is at night. • Think about which light rhythm in the list is commonly associated with a preferred channel mark (where the main channel is on one side of the buoy). • Ask yourself: which of these light characteristics would most likely be reserved for a more specialized lateral mark, rather than an ordinary port-hand mark along the edge of a channel?

✅ Before You Answer

• Verify how simple port-hand lateral marks (not bifurcation marks) are shown in IALA-A: color, shape, and typical light rhythms. • Check which characteristic (especially Group Flashing (2 + 1)) is associated with a preferred channel mark rather than a standard lateral mark. • Confirm that quick flashing, isophase, and long flashing can all be used as basic rhythms on standard lateral marks in many buoyage systems, and compare that to the special group flashing pattern.