In fog, one prolonged blast every two minutes. Who is it?
A power-driven vessel making way through the water.
Rule 35 (a).
Part of the convention Sound and light signals
In or near an area of restricted visibility, day or night. The core: one prolonged blast every 2 minutes at most means a power-driven vessel making way through the water; two prolonged means underway but stopped; one prolonged and two short means the special category; one prolonged and three short means a vessel towed.
- One prolonged and two short is sounded by: not under command, restricted in ability to manoeuvre, constrained by draught, sailing, engaged in fishing, towing or pushing. Fishing and RAM vessels working at anchor sound it too.
- At anchor: rapid ringing of the bell for about 5 seconds at intervals of not more than a minute. From 100 m: the bell forward and immediately the gong aft. She may add short, prolonged, short to warn an approaching vessel.
- Aground: three separate distinct strokes of the bell before and after the rapid ringing.
- A vessel from 12 up to 20 m need not sound the bell signals, and a vessel under 12 m need not sound any of the signals above at all. Both, however, must make some other efficient sound signal at intervals of not more than 2 minutes.
- A pilot vessel on duty may add an identity signal of four short blasts.
At sea it looks like this
In fog you hear one prolonged blast forward of the beam: that is a vessel with way on. Rule 19 requires you to cut to minimum speed at once and be ready to stop.
The rule says«In or near an area of restricted visibility, whether by day or night, a power-driven vessel making way through the water shall sound at intervals of not more than 2 minutes one prolonged blast».
Sound signals
Sound signals
▬Power-driven vessel making way through the water
▬ ▬Power-driven vessel underway but stopped
▬ • •Not under command, restricted in ability to manoeuvre, constrained by draught, sailing, fishing, towing or pushing
▬ • • •Vessel towed, or the last vessel of the tow if more than one
bell ≈5 s, every 1 minVessel at anchor
3 strokes + bell + 3 strokesVessel aground
• • • •Identity signal of a pilot vessel
Check yourself
In fog, two prolonged blasts about two seconds apart. Who is it?
A power-driven vessel underway but stopped, with no way on.
Rule 35 (b).
In fog, one prolonged and two short blasts. Who can be sounding that?
Not under command, restricted in ability to manoeuvre, constrained by draught, sailing, fishing, towing or pushing.
Rule 35 (c).
In fog, one prolonged and three short blasts. Who is it?
A vessel towed, or the last vessel of the tow, when manned.
Rule 35 (e).
How do a vessel at anchor and a vessel aground sound in fog?
At anchor, rapid ringing of the bell for about 5 seconds every minute (from 100 m, bell forward and gong aft). Aground, the same plus three separate strokes before and after.
Rule 35 (g), (h).
Four short blasts. Who sounds them?
A pilot vessel engaged on pilotage duty, as an identity signal.
Rule 35 (k).
At what intervals are fog signals sounded?
On the whistle, not more than every 2 minutes. The anchor bell, not more than every minute, ringing for about 5 seconds.
Rule 35.