The BSS checklist
What a Boat Safety Scheme examiner checks, the ten things boats fail on most, and how to get your boat ready.
The short answer. A BSS examination checks that your boat meets its navigation authority's minimum safety requirements on the day. Checks marked R (requirement) must pass for a certificate. Checks marked A (advice) are recommended, but a privately owned boat still gets its certificate without them. A certificate usually lasts four years less one day. Find an examiner on the official BSS register.
The ten checks boats fail most often
The Boat Safety Scheme's own list, from the 21,000 or so examinations it says are carried out each year. The check number is in the BSS Examination Checking Procedures.
| What fails | Check | What to do |
|---|---|---|
| Batteries not held secure | 3.1.2 | Strap, bracket or frame each battery so it can’t move more than 10 mm any way. Put the restraints back after changing a battery. |
| Gas leak in the tightness test | 7.12.2 | Never ignore a smell of gas. Use a bubble tester if one is fitted. If in doubt, get a Gas Safe engineer qualified for boats. |
| Wrong number or rating of fire extinguishers | 6.1.1 | See the table below for your boat’s length. |
| No CO alarm, or too few | 6.4.1 | At least one alarm in the accommodation, certified to BS EN 50291. Test it regularly. |
| Gas pipe joints loose or badly made | 7.8.4 | Look over gas hoses and joints, and use the bubble tester if you have one. |
| Fuel shut-off valve hidden and not marked | 2.13.3 | Leave it in view, or mark where it is. |
| Battery isolator hidden and not marked | 3.6.5 | Mark where it is with a permanent label. |
| Gas burners not burning properly | 8.8.1 | A burner should give a blue flame. Get a yellow or flickering flame looked at. |
| Main gas shut-off valve hidden and not marked | 7.6.2 | Leave it in view, or mark it with a permanent label. |
| Cables not supported safely | 3.3.1 | Clip wiring so it can’t trip anyone or snag. |
What each part of the exam covers
For privately owned boats the checks come in eight parts, numbered 2 to 9.
- Part 2: Fuel systems and fixed engines
- Fuel can’t spill inside the boat when you fill up. The filling point is marked with the fuel type. Each tank has a vent. Shut-off valves are in view or marked.
- Part 3: Electrical systems
- Cables insulated and supported. Batteries secure and in a ventilated space if open-vented. An isolator for each battery or bank. Fuses and breakers undamaged.
- Part 4: Electric propulsion
- Only if the boat is driven by an electric motor.
- Part 5: Outboards, portable engines and spare fuel
- How outboards, portable fuel tanks and spare petrol are stored.
- Part 6: Fire extinguishers, fire blanket and CO alarms
- The right extinguishers for the boat’s length, a fire blanket near a fixed cooker, and CO alarms in the accommodation.
- Part 7: Gas (LPG)
- Where the cylinders are kept and that the locker is gas-tight, pipes and hoses, shut-off valves, and a tightness test of the whole system.
- Part 8: Appliances and flues
- Cookers, heaters and stoves: fuel supply, protection against fire, flues, and that gas burners burn properly.
- Part 9: Pollution
- An oil-tight tray under the engine and gearbox, and how bilge pumps and toilets are set up.
Fire extinguishers
Each extinguisher must be rated at least 5A/34B, carry a third-party certification mark, and be in good condition: safety pin in, no dents or serious rust, hose not perished, and any gauge out of the red. Together they must reach the combined rating for your boat's length (check 6.1.1).
| Length of boat | At least | Combined rating |
|---|---|---|
| Under 7 m (23 ft) | 2 extinguishers | 10A/68B |
| 7 to 11 m (23 to 36 ft) | 2 extinguishers | 13A/89B |
| Over 11 m (36 ft) | 3 extinguishers | 21A/144B |
You can have one 5A/34B extinguisher fewer if the boat has no internal combustion engine, or no fuel-burning appliance. Extinguishers must be spread around the boat, easy to reach, and in view or marked with a label (checks 6.1.2 and 6.1.3). A boat with a fixed cooker also needs a fire blanket to BS EN 1869 or BS 6575, near the cooker (checks 6.2.1 and 6.2.2).
Carbon monoxide alarms
- How many
- At least one in any boat with accommodation, and one within 10 m of every door that links accommodation spaces (check 6.4.1).
- What kind
- In open view, certified to BS EN 50291, with a test button (check 6.4.3).
- Condition
- Undamaged, not past its replacement date, and it must sound when tested (check 6.4.4). If no fitting date is written on it, count 10 years from the date it was made.
- Near a stove
- Where a solid fuel stove and berths share a space, an alarm there is advised (check 6.4.2, advice).
Getting the boat ready
An examiner can't issue a certificate after an incomplete examination. If something can't be checked, they may have to come back. Before they arrive, have:
- Gas or fuel on board, so the examiner can light the cooker, heater and boiler.
- Batteries charged and water in the system, if the appliances need them.
- Access panels and covers off, so gas joints, gas hoses and fuel hoses can be seen and touched.
- The gas locker unlocked and emptied of loose items, mats and false floors. The examiner may need to take the connected cylinders out.
- Shore power and battery charging switched off if it’s safe to, and the shore-power lead out ready to look at.
- Any paperwork showing a part meets its standard, for example engine hoses made to ISO 7840.
- Your last certificate number and expiry date.
- Keys, and access to the mooring, with the landowner told if needed.
Booking, failing and what it isn't
- Book early
- If your current certificate has two months or less to run, a new examination keeps the old expiry day and month, plus four years. So you lose nothing by going early.
- If it doesn't pass
- The examiner tells you which requirement checks failed and what's needed. In general you have up to three calendar months for a re-examination of those items.
- Warning notice
- Issued if the examiner finds, or suspects, a significant and immediate risk. Make the boat safe as soon as possible.
- It isn't a survey
- The exam is not a full condition survey. It doesn't cover the hull, through-hull fittings, stability or the general state of the engine. It only shows the boat met the requirements on the day.
- Keeping it valid
- You must keep the boat meeting the requirements all the time. A certificate can be cancelled if the boat isn't maintained or is altered so it no longer complies.
- Tell your insurer
- The BSS advises telling your insurer or broker about any failed advice checks, as they may matter to your cover. Narrowboat insurance, firms A to Z.
Where this comes from
- BSS Core Examination Checking Procedures, Edition 5, July 2023 (PDF)
- BSS: the 10 most common non-compliances
- BSS: preparing for examination
- BSS: certification, what it is and what it is not
- BSS: advance booking
- BSS: if your boat does not pass
Read on 20 October 2026. Boat Safety Hub is independent and is not part of the Boat Safety Scheme. If anything here differs from the BSS's own documents, theirs is right.