Lights and shapes of vessels — What she is
Reading notes · Lights and shapes of vessels
Eleven configurations in three families, grouped by what you see and not by rule number: no colour above the sidelights, a pair one over one, or a string of reds. And the tow, which is none of them.
Open the interactive chapter →The same material with the chart, the drawings and the exercises.
What she is · topic 4
The black water between them
Here is the configuration that kills people. A tug ahead, a tow astern, and between them a hundred and twenty metres of wire with not one light on it.
What you see at night is two separate groups of lights, and the natural reading — two vessels, pass between them — is the reading that puts a wire across your foredeck.
So the question is never «what are those lights». It is «is there anything between them», and the answer is on the tug: a vertical stack of masthead lights where an ordinary vessel has one, and a yellow light above her sternlight, and nothing else carries a yellow there.
See a yellow over a sternlight and assume there is a wire, until you have seen what is on the end of it.
From astern, two lamps are the whole warning
Now from abaft her beam, which is where you meet one when overtaking. The stack has cut off — masthead lights stop at 112.5° — and what is left on the tug is her sternlight and the yellow above it.
Further off, and lower, the tow shows her own sternlight. Two white lights at different distances, one with a yellow above it.
That is the whole warning, and it is two lamps. Miss the yellow and you have two unrelated vessels; see it and you have one tow and a wire you must go round.
And notice what you have lost: from here you cannot count the stack, so you know she is towing and you do not know how much of it there is.
What she is · topic 5
What you can name now
That is every configuration this part teaches, and there are eleven of them. Not a hundred: eleven. The rules hold a few more — a vessel aground is one, and you will meet her in part 4 — but these are the ones you will see most and the ones the examiner starts with. Ten of them have a rule of their own; the odd one out is a sailing vessel using her engine, which borrows Rule 23 and is the reason you cannot tell her apart at night.
And they came in three groups, not eleven separate lessons — which is the whole point of the way this part is built. Ask three questions in order and every one of them falls out: is there a coloured light above her sidelights? Is it a pair, one over one? Or is it a string of reds?
Underneath all eleven is the question the rules were written to answer: can she get out of your way? A clear deck means yes. A string of reds means no. Everything else is somewhere in between.
What you cannot do yet is read her from where you are. Every screen here has shown you a vessel from her starboard side, whole, with her hull drawn — a diagram, not a sight. At two miles on a black night there is no hull, and half of what you have seen is not there. That is part 3, and it is the part that turns this into seamanship.
Open the interactive chapter →The same material with the chart, the drawings and the exercises.