How did you get on?
Rule 21 deals with the arcs of visibility.
Have a look at this.
If you can only remember one number, remember the stern light, after that it’s just a case of simple maths. 360 - 135 = 225 which happens to be 2 side lights (112.5 each).
Rule 22 deals with the visibility of lights. (numbers are in nautical miles)
| Light | Colour | Placement | More than 50m | Between 50 and 12m | less than 12m |
| Masthead Light | White | Centreline | 6 | 5 (3 if less than 20m) | 2 |
| Sidelight | Red or Green | On or close to the side | 3 | 2 | 1 |
| Sternlight | White | On or close to the stern | 3 | 2 | 2 |
| Towing light | Yellow | Close to the Stern | 3 | 2 | 2 |
| All-round light | White, Red, Green, Yellow | Where it can best be seen | 3 | 2 | 2 |
Well done if you manage to answer that with ease.