Every week, we present you with a question about your boating license. Whether you're looking to validate your knowledge or discover new and unexplored areas. This week, we take a look at a question on ship's lights and markings.
Green, red and 2 white
If I see a green light and a red light at the same time, it means I'm exactly in line with the ship's course. In fact, the lights are designed to intersect on a few degrees. The RIPAM specifies that "The intensities of the sidelights (main beam lights) must decrease to practically zero between 1 and 3 degrees outside the prescribed sectors." It is therefore normal to see these two lights in this specific situation.
The two superimposed white lights indicate that this is a tugboat. In fact, a mechanically propelled vessel under tow must show :
- Two superimposed masthead lights (white visible at 225°)
- Side lights (two-tone red and green, each visible for 112.5°)
- A stern light (white visible over 135°)
- A towing light above the stern light (yellow, visible at 135°)
The towing light is only switched on when towing. It is not used for torque towing.
We also deduce that this tug is less than 50 m long, otherwise it would also have a white masthead light at the bow.
What's more, the entire tow (tug + towed boat) is less than 200 m long. Indeed, if it had been longer than 200 m, the tug would have had a third white light superimposed.
The diagram above shows an aerial view. It's as if we were sailing the motorboat and discovering the tug. In any case, we need to change course to avoid interfering with the tug.
