Navigation General · IALA Marks
A safe water mark (e.g., a mid-channel or landfall buoy) is colored:
- ASolid green
- BSolid red
- CBlack and yellow
- DRed and white vertical stripes, often with a single red spherical topmark✓ Correct
Explanation
Safe water marks have red and white vertical stripes and may carry a single red ball topmark. They indicate navigable water all around (mid-channel or landfall) and often show a Morse 'A' or long-flashing white light.
Authority: IALA Maritime Buoyage System; USCG Light List
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