Seaplanes
Where it is impracticable for a seaplane to exhibit lights of the exact characteristics, it shall exhibit lights as closely similar as possible.
Rule 31 states that where it is impracticable for a seaplane or WIG craft to exhibit lights and shapes of the characteristics or in the positions prescribed in Part C, she shall exhibit lights and shapes as closely similar in characteristics and position as is possible.
Recognition Sequence
Classify the vessel state first: underway, making way, stopped, at anchor, aground, towing, fishing, pilotage or special condition.
Read special lights vertically from top to bottom before using sidelights and sternlight to confirm aspect.
Then confirm the answer with the day shape, vessel length and any extra signal such as towing lights, deck illumination or a cylinder.
Exam Focus
Avoid identifying a vessel from one colour alone. Many mistakes come from spotting a red light and guessing before checking the full pattern.
If the question mentions 'making way', 'underway but stopped', 'at anchor' or 'aground', that wording usually determines which extra lights or shapes appear.
Key Takeaways
Seaplanes must exhibit lights as similar as practicable to the rules
WIG craft are also covered by this rule
Practical limitations are acknowledged
Common Mistakes
Assuming seaplanes are exempt from showing navigation lights
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