Are You a Navigation Lights Pro? Take the Nav Rules Quiz!
Think you can ace this navigation lights quiz? Level up your maritime navigation practice now!
Use this Nav Rules quiz to practice navigation lights and spot what each vessel should show at night or in fog. Answer short, real-world questions to check gaps before an exam or your next trip on the water. Start now - take the first quiz and build confidence with more drills.
Study Outcomes
- Identify Navigation Light Configurations -
Recognize the specific colors, placements, and characteristics of vessel navigation lights to correctly answer questions in our nav rules practice test.
- Apply Nav Lights Regulations -
Interpret international nav lights regulations to determine compliance requirements for different vessel types and operating conditions.
- Interpret Light Signal Meanings -
Analyze various light signals to understand right-of-way, vessel status, and safe sailing protocols during our navigation rules quiz.
- Differentiate Operational Scenarios -
Distinguish between navigation light requirements for power-driven, sailing, and anchored vessels under daytime and nighttime conditions.
- Evaluate Compliance Strategies -
Assess real-world situations to ensure correct nav lights are displayed, reinforcing best practices before taking the maritime navigation practice test.
- Prepare for the Nav Rules Practice Test -
Employ test-taking strategies and focused review techniques to boost your confidence and accuracy on the vessel navigation lights quiz.
Cheat Sheet
- COLREG Color Sectors -
Under Rule 21 of the International Regulations for Preventing Collisions at Sea (COLREGs), port-side lights display red over an arc of 112.5°, starboard-side lights display green over 112.5°, and a white stern light covers 135°. Memorize "Red on Port, Green on Starboard, White on the Stern" to ensure you can identify vessel headings at night.
- Geographic Range Formula -
The maximum distance at which a light is visible depends on the height of the light above water: d = 2.08 × (√h + √h₂) nautical miles, where h and h₂ are the heights in meters of observer eye and masthead. For example, a masthead light 9 m high seen by an observer 4 m above water yields d ≈ 2.08 × (3 + 2) ≈ 10.4 NM.
- Nominal Range & Luminous Intensity -
Nominal range refers to the distance a light is seen in standard atmospheric conditions and is determined by luminous intensity using the inverse-square law E = I/r², where E is illuminance, I is intensity in candelas, and r is distance in meters. IMO Resolution A.227 charts help match intensity to nominal range - for instance, 25 cd for a 2 NM visibility.
- Vessel Lighting Configurations -
COLREG Rule 23 requires vessels under 50 m to show a single masthead light and those 50 m or more two masthead lights in a vertical line. Boats under 12 m may combine sidelights and stern light into one lantern. Always consult U.S. Coast Guard Nav Rules publications for specific vessel-length adaptations.
- Anchoring & All-Round Lights -
When at anchor in open water, vessels under 50 m must display an all-round white light visible at 2 NM; vessels 50 m or more show two all-round whites - one forward and one aft. Rule 30(b) of the COLREGs specifies these requirements to prevent collisions in restricted visibility.