CEVNI Sound Signals and Reduced Visibility

Prerequisites

You should know the COLREGs manoeuvring signals (one, two and three short blasts) and fog signals at Day Skipper level, and the CEVNI lights and day marks from the previous lesson. A basic idea of VHF use (an SRC or equivalent operator certificate) helps for the radio section.

Learning Objectives

• State the length of a short blast, a long blast and a series of very short blasts.
• Give the meaning of the CEVNI general signals (Annex 6): one long, one to four short, a series of very short blasts and distress.
• Use and recognise meeting, overtaking, turning and harbour entry or leaving signals.
• Know how a small craft should behave in reduced visibility and what signals stationary and moving vessels give.
• Explain how radar navigation and VHF are used between large vessels in poor visibility, and how that affects you.
• Name the inland VHF arrangements (RAINWAT, ATIS) and the usual ship-to-ship channel.

Sound signals on inland waters

CEVNI sets out sound signals in Chapter 4 and lists them in Annex 6. Many are the same as COLREGs, some are new, and a few look the same but are used differently. The RYA G17 European Waterways Regulations and the RYA Handy Guide to CEVNI both reproduce the table; the CEVNI test asks you to identify signals both ways round (meaning from signal, and signal from meaning).

Blast lengths

In this lesson, S means a short blast and L a long blast. So "L L S" is two long blasts followed by one short.

Vessels other than small craft must have a horn that meets the rules; motorized small craft should carry a horn and small craft generally should be able to make the signals they need. A small portable air horn is fine for a yacht or hire cruiser.

When a vessel gives a sound signal, large vessels also show a yellow light flash in time with it on many waterways. You may see a yellow flashing light on the bridge of a barge at the same time as you hear the horn.

General signals

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How these differ from COLREGs

• One long blast means "attention". At sea a prolonged blast is used in fog or at a blind bend. Inland, one long blast is a general "look out" signal, used for example when a vessel is about to do something that others must notice.
• Four short blasts is "unable to manoeuvre". There is no COLREGs equivalent.
• Danger of collision is a series of very short blasts. At sea, five or more short blasts mean "I doubt your intentions". Inland, the danger signal is a rapid series of very short blasts. Five short blasts appear in CEVNI only as the reply "you cannot overtake me" (see below). Do not confuse them.

Meeting signals

When two vessels meet, the normal rule inland is to pass port to port. Vessels other than small craft use radio first (see below). If they cannot agree by radio, the meeting signals are:

The upstream vessel decides the side. The downstream vessel repeats the signal to confirm. The blue board and white scintillating light do the same job visually. Small craft do not normally make meeting signals to large vessels: they simply keep clear early.

Overtaking signals

When overtaking is not agreed by radio, the overtaking vessel asks, and the vessel being overtaken replies.

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The replies make sense if you think of what the overtaken vessel does: one short blast means "I am moving to starboard", which opens up its port side; two short means "I am moving to port", which opens up its starboard side. If the vessel being overtaken wants the overtaking to happen on the other side from the one asked for, it gives the reply for the side it prefers, and the overtaking vessel must confirm by repeating it.

Five short blasts means overtaking is not possible here, for example in a narrow stretch or a bend. The overtaking vessel must wait.

Remember that the overtaking vessel gives way to the overtaken vessel until it is past and clear, as at sea.

Turning signals

Inland vessels often turn round (wind) in the river. A long barge turning across the fairway blocks it completely for a short time.

The signal is given before the turn begins. Other vessels must, as far as necessary and possible, change speed and course to let the turn happen. Turning is allowed only after the vessel has made sure that it can turn without danger and without forcing others to manoeuvre suddenly. Many waterways only allow turning in marked turning areas (sign E8).

Entering and leaving harbours, tributaries and berths

These are given by a vessel coming out of a harbour or tributary into the main fairway, and by a vessel about to enter one. Vessels already in the main fairway generally have priority. A vessel leaving a berth gives the turning signal if it must turn, or the harbour signals if it must cross the fairway.

A small craft leaving a marina into a busy river is expected to wait for a clear gap, not to sound its horn and push out. The signal informs; it does not give you priority.

Signals at locks and bridges

On many waterways you may call a lock or a movable bridge by sound signal where no radio contact is available, usually one long blast. The lock or bridge answers with lights. National rules and local signs (sign B7 means "give a sound signal") tell you what to do at each structure. Never pass a red light at a lock or bridge.

Reduced visibility

What counts as reduced visibility

Inland, visibility is reduced by fog, mist, snow, heavy rain or smoke. It becomes "reduced visibility" in the rules when it is poor enough that vessels cannot see each other in good time to apply the normal rules. On a river 100 m wide with bends, that can be quite a modest fog.

The basic rule

In reduced visibility, a vessel may only continue under way if it navigates by radar, with the equipment and qualified crew the national rules require. Others must stop and moor, or go to a berth, as soon as safe. Small craft without radar should not navigate in fog at all. If fog comes in, get out of the fairway and moor or anchor clear of it.

Signals of vessels under way in fog

A vessel under way in reduced visibility without being able to see others gives one long blast at intervals of not more than one minute. Other vessels navigating by radar use radio first (see below); if they cannot make contact they give sound signals as the rules require. On some waterways, radar vessels coming downstream sound a three-tone signal (three blasts on different pitches) repeated at intervals. Check the national rule; you are most likely to meet it on the Rhine.

Signals of stationary vessels in fog

A vessel stationary in or near the fairway in reduced visibility (other than a small craft, which should be moored clear) rings a bell at intervals of not more than one minute:

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Left and right banks are named looking downstream. If you have moored up in fog on a busy waterway, keep a horn and torch ready and keep a listening watch on VHF.

Ferries in fog

Ferries not moving independently and ferries crossing under power have their own fog signals in some national rules. If you hear an unfamiliar signal near a ferry crossing, stop and listen.

Radar navigation

Large inland vessels normally have radar and an inland ECDIS, and many carry Inland AIS. In reduced visibility, a vessel navigating by radar must keep a constant listening watch on the ship-to-ship channel. When it sees another vessel approaching on the radar, it calls it by VHF and agrees a passing side. The upstream vessel still decides the side, as in the meeting rules.

Your small craft is a weak radar target, especially a wooden or GRP boat without a radar reflector. A barge skipper may simply not see you. That is why the rule for small craft is to keep out of the fairway in fog, and why a good radar reflector is worth fitting.

If you do carry radar, use it to stay clear, not to compete for the channel. Practise in clear weather before you rely on it.

VHF on inland waterways

RAINWAT and ATIS

Inland VHF in most of Western Europe is run under the Regional Arrangement on the Radiotelephone Service on Inland Waterways (RAINWAT, often called the Basel Agreement). Key points:

• Radios used on these waterways must transmit an ATIS code: a digital identification sent automatically at the end of every transmission. A normal marine radio can usually be programmed with an ATIS code; the code is based on your MMSI and is issued by your licensing authority (Ofcom in the UK).
• DSC must not be used on RAINWAT inland waters; most dual-mode radios have an inland mode that switches DSC off and ATIS on. Remember to switch back at sea.
• Ship-to-ship transmissions use low power (1 watt).
• You need an operator certificate. The UK SRC is generally accepted, but some countries require an inland radio endorsement (for example a UBI certificate in Germany and the Netherlands). Check the current national rule.

Channels

Channels vary between countries and waterways. Signs on the bank show the channel to use for locks and bridges, and pilot guides list them. Listen on the ship-to-ship channel on busy rivers: you will hear barges agreeing passing sides, often in Dutch, German or French, and you will learn what they plan to do.

A barge may call you. A short reply in English, giving your position and stating that you will keep to one side, is usually welcome. Keep it brief and use the vessel's name if you can read it.

Worked Example

Scenario 1: overtaking on a river

You are motoring downstream at 10 km/h in a hire cruiser. A barge behind you sounds two long blasts followed by two short blasts.

1. L L S S means "I want to overtake you on your port side".
2. If it is safe, you reply with one short blast (S): "you may overtake on my port side", and move to starboard.
3. If there is a moored vessel or a bend ahead on your starboard side and you cannot give room, you reply with five short blasts: "you cannot overtake me", and then give room as soon as you can.

Scenario 2: a barge turning

Approaching a wide basin, you hear one long blast followed by two short blasts from a barge ahead.

1. L S S means "I am turning round to port".
2. Slow down, stay well clear astern and let it complete the turn. Expect its stern to swing across the river.

Scenario 3: fog comes in

You are cruising upstream on a big river in the morning. Mist thickens and you lose sight of the banks 100 m away. You hear one long blast every minute somewhere ahead, and later two strokes of a bell from close by.

1. You have no radar. You must leave the fairway and moor as soon as safe.
2. The long blasts are a vessel under way in fog. The two bell strokes are a stationary vessel on the right bank.
3. You call on channel 10 with your position, move slowly to the edge of the fairway, and moor at the first safe place, away from the stationary vessel.

Common Mistakes

• Thinking five short blasts means "danger" inland. In CEVNI, danger of collision is a series of very short blasts. Five short means "you cannot overtake me".
• Getting the overtaking replies backwards. The overtaken vessel's one short blast means "you may pass on my port side", because it moves to starboard.
• Treating a long blast as fog only. Inland, one long blast is "attention".
• Forgetting ATIS. Using DSC or a radio without ATIS on RAINWAT waters is not allowed. Set the radio to inland mode.
• Carrying on in fog without radar. Moor clear of the fairway.

Summary

• Short blast about 1 second, long blast about 4 seconds.
• L attention; S starboard; S S port; S S S astern; S S S S unable to manoeuvre; a series of very short blasts danger of collision; repeated long blasts or a bell distress.
• Overtaking: L L S (your starboard side), L L S S (your port side). Replies: S (my port side), S S (my starboard side), S S S S S (cannot overtake).
• Turning: L S to starboard, L S S to port.
• Harbours and tributaries: L L L S (heading to starboard), L L L S S (heading to port).
• In reduced visibility, only radar vessels continue; small craft moor clear. Under way: one long blast each minute. Stationary: bell 1, 2 or 3 strokes for left, right or undetermined.
• Inland VHF uses RAINWAT: ATIS on, DSC off, low power, ship-to-ship usually channel 10.

Check Your Understanding

1. What does four short blasts mean in CEVNI?

Answer: I am unable to manoeuvre.

1. A vessel sounds a series of very short blasts. What does it mean?

Answer: Danger of collision.

1. A barge astern sounds L L S. What does it want?

Answer: To overtake you on your starboard side. If safe, you reply S S and move to port.

1. You are being overtaken but there is no room. What do you sound?

Answer: Five short blasts: you cannot overtake me.

1. What does one long blast followed by one short blast mean?

Answer: I am turning round to starboard.

1. A vessel leaving a harbour into the main river and heading to port sounds what?

Answer: Three long blasts and two short blasts (L L L S S).

1. In fog you hear three strokes of a bell repeated each minute. What is it?

Answer: A stationary vessel in an undetermined position in or near the fairway.

1. What is ATIS and when must it be used?

Answer: An automatic digital identification sent at the end of each VHF transmission. It is required on inland waterways under the RAINWAT arrangement, with DSC switched off.

1. What is the usual ship-to-ship VHF channel on inland waterways?

Answer: Channel 10, though some waterways use others. Check local signs and guides.