Fanali e segnali — Tabella riassuntiva

How to use this cheat sheet

Drill the same content interactively

• Study by images (3D)Same vessels, 3D models you can rotate — for when the static cheat sheet isn't enough.
• Test by images — vessel ID quizA vessel appears with no label — name it from the lights alone.
• Lights & shapes hub (Rules 20–31)Open any rule for the full legal text, common mistakes and FAQ.
• NUC vs RAM — the two reds people confuse mostSide-by-side of "not under command" and "restricted in ability to manoeuvre".

Frequently asked questions

Can I print this cheat sheet?

Yes. Use your browser's Print menu and choose "Print to PDF" or send it to a colour printer. For best results: landscape orientation, fit-to-page, no scaling. The legend bar and filter controls don't print — only the diagrams and labels do.

What's the difference between a vessel < 50 m and ≥ 50 m?

At 50 m or more, COLREG Rule 23(a)(i)+(ii) requires a SECOND masthead light aft, higher than the forward masthead. Below 50 m the second masthead is optional. This single boundary is the most-tested length cut-off in Part C, so the cheat sheet groups every row that has both variants side by side.

Why are some vessels shown with extra cones or balls on the sides?

Rule 27 covers vessels engaged in special operations: minesweeping (three black balls in a triangle), fishing with gear extending more than 150 m horizontally (a cone apex-up in the direction of the gear), dredging or underwater operations with obstructions on one side (two red balls one side, two green balls the other). These side-mounted shapes are added on TOP of the base configuration, never instead of it.

Do these lights apply at anchor?

No — anchored vessels follow Rule 30, not the underway rules in 23–28. The cheat sheet has a separate row for "vessel at anchor" (one all-round white forward, or fore + aft if ≥ 50 m, plus the option to illuminate the deck if ≥ 100 m). A vessel aground adds two red all-round lights in a vertical line and the day equivalent (three black balls).