🔍 Key Concepts

• IALA Buoyage System characteristics for a Safe Water Mark (color, shape, topmark, light) • Differences between Safe Water Marks and Cardinal/Preferred Channel Marks • Standard light rhythms used on Safe Water Marks (e.g., Morse "A", long-flashing, isophase/occulting)

💭 Think About

• Which of the choices describes a light characteristic or feature that is more typical of cardinal marks rather than safe water marks? • Think about the standard shapes and colors used for safe water marks—could any option contradict those standards? • Are safe water marks allowed to have letters or specific shapes like spheres, and what color must their lights be?

✅ Before You Answer

• Verify the standard light rhythm(s) permitted for Safe Water Marks in the IALA system. • Check what shapes (including spherical, pillar, or spar) are allowed for Safe Water Marks and what topmark they carry. • Confirm whether Safe Water Marks may carry letters and what light color they are required to show (if they are lit).