How to study navigation lights and day shapes
Lights and shapes become easier when you study the vessel's condition, viewing aspect and rule reference together.
Identify the vessel condition
Before naming a light pattern or shape, determine what the vessel is doing or what condition the scenario describes.
Determine the viewing aspect
Ask where the observer is relative to the vessel. A diagram can look different from the bow, stern or either side even when the vessel's required display has not changed.
Connect the diagram to the rule
Use the diagram as a recognition exercise, then read the applicable text in Rules 20 through 31. The image supports the rule; it does not replace it.
Practice in both directions
Given a diagram, identify the likely vessel and condition. Given a written scenario, picture the lights or day shapes that should be visible from the stated aspect.
Frequently asked questions
Which COLREGS rules cover lights and shapes?
Rules 20 through 31 address lights and shapes. The exact rule depends on the vessel and operating condition described.
How many diagrams are included in COLREGS Prep?
COLREGS Prep includes 87 reference diagrams and displays the relevant illustration directly with diagram questions.
Can I review only diagram questions?
The study tool lets you focus on diagrams and other topic groups, then return to mixed review when you are ready.
Practice with the complete study tool
COLREGS: Rules of the Road includes 1,272 questions, 87 diagrams, spaced repetition, quizzes, missed-question review and official rule references. It is a one-time purchase for iPhone and iPad.
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