COLREGS quiz: Lights and Shapes Practice
Quick, free lights and shapes quiz with instant results.
This quiz helps you practice COLREGS lights and shapes so you can recognize vessel lights, day shapes, and what they signal. Use it to spot gaps before an exam or a watch and to sharpen recall under time. If you're brushing up on wider rules, try our nav rules practice test, or build vocab with a nautical terms quiz.
Study Outcomes
- Identify Standard Navigation Lights & Shapes -
Recognize the visual characteristics of common vessel lights and shapes defined by the COLREGS, ensuring clear identification of vessel types and statuses.
- Differentiate IRPCS Light & Shape Signals -
Distinguish between various International Regulations for Preventing Collisions at Sea signals to determine vessel actions and right-of-way.
- Interpret Navigation Light Patterns -
Analyze light configurations on vessels to assess their heading, activity, and maneuvering constraints in low-visibility conditions.
- Apply Collision Regulations -
Use COLREGS rules to decide appropriate collision avoidance measures based on the observed lights and shapes of other vessels.
- Analyze Quiz Feedback -
Review instant test results to pinpoint knowledge gaps and reinforce correct understanding of collision regulations lights and shapes.
- Reinforce Maritime Navigation Concepts -
Solidify foundational knowledge of navigation light patterns and COLREGS requirements, boosting confidence for certification exams or real”world application.
Cheat Sheet
- Light Arcs and Visibility -
Understanding the exact degree arcs for navigation lights is crucial: the masthead light must cover 225°, sidelights 112.5° each, and the stern light 135° behind the beam. This knowledge, defined in COLREGS Rule 22 by the International Maritime Organization (IMO), helps determine if another vessel is on a collision course based on which lights you can see. Remember "225-112.5-135" as a simple arc reference to keep the numbers handy.
- Colour Conventions and Positions -
Port and starboard sidelights use red and green lenses respectively, with white reserved for masthead and stern lights to prevent confusion at night (COLREGS Rule 21). Always check that sidelights are mounted at a height above the heel of the vessel for clear visibility, typically no more than 1 m above the bulwark. A quick mnemonic: "Red on left, green on right, white shows who's out of sight."
- All-Round Lights vs. Sector Lights -
All-round lights emit a continuous 360° beam, used for specific vessel types like pilot vessels and small fishing boats (Rule 23), whereas sector lights target defined arcs to warn of hazards or mark approaches. For example, an all-round white light on a pilot boat must be visible through the full horizon, while a sector light might only cover 10° - 20° to highlight a safe channel. Always refer to official vessel certificates or IMO publications to confirm which light type applies.
- Day Shapes for Special Categories -
Day shapes communicate vessel status: a vertical cone up indicates fishing with nets, two cones base-to-base signal restricted maneuverability, and a ball-diamond-ball shows mine clearance operations (Rule 27). Learn the "ball-diamond-ball" pattern by visualizing a smiley face: ball for eyes, diamond for a nose, ball for a mouth. Consistent practice with diagrams from maritime academies will reinforce quick identification.
- Towing and Fishing Signals -
Towing vessels display three white lights in a vertical line when the tow exceeds 200 m, plus a diamond shape where it can best be seen (Rule 24). Fishing vessels engaged in trawling show a green over white light at night and two cones apex-to-apex by day - memorize "Green over White, trawling all night." Cross-check with USCG Navigation Rules Quick Reference Cards for real-world examples.
