Lesson routeThe Five Sign Families0/4 read
Lesson 1 of 4
The Five Sign Families
CEVNI signs are not decorative labels. They tell you whether something is prohibited, required, restricted, recommended, or simply indicated. Learning the family first helps you work out the action even before you memorise every individual board.
Many mistakes happen when a skipper reads a sign as information when it is actually an instruction. Build the habit of asking what the sign is doing to your options.
- Prohibitory signs remove an option: no entry, no overtaking, no berthing, no anchoring, no wash.
- Mandatory signs require an action: proceed in a direction, keep to a side, stop, sound a signal, use radio.
- Restrictive signs limit depth, headroom, width, speed, or available channel.
- Recommendatory and informative signs guide or permit an action but still need local judgement.
| Family | Typical meaning | Skipper action |
|---|---|---|
| Prohibitory | You must not do something | Keep out, do not overtake, do not berth, do not make wash |
| Mandatory | You must do something | Follow direction, keep to side, stop, sound signal, establish radio contact |
| Restrictive | Navigation is limited | Check draught, air draught, beam, speed, or channel offset |
| Recommendatory | Preferred route or opening | Use the marked route unless unsafe or directed otherwise |
| Informative | Facility, permission, feature, or useful notice | Use the information without treating it as unlimited permission |
Lesson 2 of 4
Reading Signs in Context
An inland sign may apply to one bank, a bridge opening, a lock approach, a whole reach, or a section measured from the sign. Supplementary panels can add distance, direction, time, vessel class, or an explanatory note.
Do not separate the sign from the waterway. A no-berthing sign on the starboard bank, a speed limit beside a village, and a restricted headroom board before a bridge all require different checks.
- Check which side or opening the sign controls.
- Read any supplementary panel before deciding.
- Connect restrictions to your vessel dimensions and speed.
- Use signs early enough to avoid last-minute manoeuvres.
Watch for this: A sign that looks simple can still include a hidden distance, direction, vessel-class, or time condition.
Lesson 3 of 4
Marks and Channel Discipline
Marks and signs work together to define the usable water. Inland channels can be narrow, shallow, bounded by banks, split by bridge piers, or shared with larger vessels that cannot easily leave the fairway.
Your response is often conservative: stay in the marked fairway, avoid stopping in the channel, do not cut corners at bends, and keep clear of prohibited or restricted areas.
- Use marks to maintain the fairway rather than wandering across the width of the waterway.
- Treat bridge and lock approaches as controlled water until you know otherwise.
- Keep away from weirs, work areas, ferry routes, and signed closed sections.
- Slow down early where signs indicate wash, speed, or traffic restrictions.
Lesson 4 of 4
Exam and Real-World Traps
Multiple-choice questions often test the difference between similar sign families: no overtaking versus no passing, keep to a side versus move to a side, permission to berth versus prohibition on berthing.
On the water, the common trap is late recognition. If you see the sign too close to the lock, bridge, bend, or commercial vessel, the correct rule may no longer be easy to apply safely.
- Prohibited means do not do it.
- Mandatory means do it as directed.
- Restriction means check whether your boat can comply.
- Recommendation means preferred safe route, not permission to ignore other traffic.