Sound signals & day shapes
The key signals on the water — learn and recognise them.
Practice — name the signal
Which sound signal is this (short = narrow, long = wide)? Pick the meaning.
What does this mean?
Score: 0/0
Sound signals
Large vessels show a yellow all-round flashing light at the same time as the sound signal.
A small vessel may give the general signals, but when needed it must give the attention signal, the ‘I cannot manoeuvre’ signal and the distress signal.
Basics: blast duration
Very short blast
Duration about a quarter of a second.
Short blast
Duration about 1 second.
Long blast
Duration about 4 seconds.
General (manoeuvring) signals
One long blast
Attention / warning signal (e.g. blind bend or harbour entrance).
One short blast
I am turning to starboard.
Two short blasts
I am turning to port.
One long + one short blast
I am turning round to starboard.
One long + two short blasts
I am turning round to port.
Three short blasts
I am operating astern propulsion.
Four short blasts
I am unable to manoeuvre.
Main & secondary waterway
Three long blasts
I am crossing the main waterway.
Three long + one short blast
From the main to the secondary waterway to starboard (or vice versa).
Three long + two short blasts
From the main to the secondary waterway to port (or vice versa).
Bridges & locks
One long, one short, one long blast
Request to operate a movable bridge or a lock (art. 6.26 / 6.28).
Danger & distress signals
Series of long blasts
Distress signal — I am in distress and need help.
Series of very short blasts
Risk of collision.
Short–long–short–long …
Keep-away signal — keep your distance (dangerous situation or cargo).
Day shapes
Black ball
The vessel is at anchor.
Cone, point down
A sailing vessel also using its engine (treated as a motor vessel).
Black cylinder
Additional day mark of an oversized seagoing vessel (BPR art. 10.03). At night: three red all-round lights in a vertical line.
Blue cones & blue lights (dangerous cargo)
The more cones or lights, the more dangerous the cargo — and the more distance you must keep when berthing. By day they are blue cones (point down), at night blue lights.
By day: blue cone(s)
At night: blue light(s)
1× cone/light
Flammable substances.
Keep 10 m clear when mooring/berthing.
By day: blue cone(s)
At night: blue light(s)
2× cone/light
Substances harmful to health (toxic).
Keep 50 m clear when mooring/berthing.
By day: blue cone(s)
At night: blue light(s)
3× cone/light
Explosive substances.
Keep 100 m clear when mooring/berthing.