Question 17

The Correct Answer is B **Explanation for Option B (Alternating red and black bands):** Buoys that mark **isolated dangers** (relatively small, isolated areas that pose a threat, with navigable water all around them) are typically painted with alternating horizontal **red and black bands**. This color scheme is standardized internationally for isolated danger marks. These buoys may also be topped with a black double-sphere topmark. **Explanation for Incorrect Options:** * **A) Alternating red and white stripes:** This color pattern is generally associated with **safe water marks** or middle ground marks (though the latter typically uses red and white vertical stripes or bands). Safe water marks indicate that navigable water surrounds the mark. * **C) Alternating green and white bands:** Green is commonly used for lateral marks (starboard side in IALA B region) or some special marks. Combining it with white in alternating bands is not the standard convention for isolated danger marks. * **D) Alternating green and black bands:** Similar to option C, this combination of colors does not adhere to the international standards (IALA system) for marking isolated dangers. Lateral marks (green or red) and cardinal/isolated danger marks (black and red/yellow) use specific combinations based on the hazard type.