Why this site exists
I am not an instructor and not a maritime lawyer. I am learning the COLREGs myself, and at some point I realised I could not hold the lights in my head: the text reads fine, but the picture never forms. So I started drawing the light configurations for myself, first on paper and then in the browser. My wife is studying the same material, and doing it together turned out to be easier. That is how a pile of home-made sketches grew into this site: first for the two of us, then in eight languages, so that nobody else has to draw it all over again.
Where the rule wording comes from
The wording follows the Convention on the International Regulations for Preventing Collisions at Sea, 1972, as amended. The printed source used for checking is the edition by Morkniga, Moscow, 2010, ISBN 978-5-903080-73-1, which carries the authentic English text alongside the Russian translation. Short excerpts are quoted with attribution; everything else is my own study retelling. This site does not replace the official IMO publication - where the two differ, trust the publication, not me.
How the diagrams are made
Every light configuration is computed from the wording of the rule: where each lamp sits, what arc of visibility it has, and what remains visible from ahead, from the starboard beam and from astern. That is why the same vessel is shown from three sides - that is exactly how it is identified in the dark. The sound signals are synthesised in the browser to Annex III: a short blast of about one second, a prolonged blast of four to six, so long signals really do take as long as they do at sea.
What is not here
No advertising, no registration, no paywalled sections. Your flashcard progress is kept in your own browser and is never sent anywhere. The visit counter loads only after you press Accept - before that, nothing is loaded at all.
If you find a mistake
Write to [email protected]. I am not infallible, and the subject here is safety at sea: an error in a light diagram costs more than a typo. If you are a seafarer, an instructor or a cadet and you see something wrong, tell me - I will fix it and say what was fixed. I answer the mail myself.
Paul LeroyProject author[email protected]