Learning

Mistake Library

The archive of the most common mistakes, with the typical consequence and a link to the page explaining how to avoid them.

Which page governs. This section is a view over the pages of the twelve modules: it collects and orders, it does not add. The authoritative treatment sits in the page linked from each entry, which carries the regulatory reference with the precise provision, the revision stamp and the content fingerprint. Where the two diverge, the page governs.

Educational use. This view supports study, familiarisation and preparation. It does not certify competence or compliance and does not replace the SMS, approved procedures or documents, authority decisions, or verification of current sources. If content differs, the linked topic governs.

Search Topic Consequence

Topic	Mistake	Typical consequence	Page
Ro-pax drill: vehicle-deck fire and SMS follow-up	Treating fire response and passenger management as one generic objective	The debrief cannot show which part worked or requires follow-up	View page →
PSC documentary preparation — passenger / ro-ro ship	Using Annex IV as an identical list for every ship	Confuses inclusion in the Annex with applicability to the ship Record scope and the reason for applicability	View page →
TMSA: the Company's self-assessment, not the ship's	Level declared from a procedure alone, without cumulative criteria and operational evidence	Maturity overstated against implementation	View page →
CDI-M: the Ship Inspection Report for chemical tankers, gas carriers and beyond	Select an inspection type without checking the relevant Chapter 5	The report may cover a different scope from that requested by the customer. Confirm vessel and inspection type, edition and Chapter 5; identify the separate reports needed for Combination.	View page →
IOPP Certificate: Reading the Certificate and Supplement Together	Compare the system with a superseded supplement	A discrepancy between actual configuration and certified documentation may remain hidden. Check the pertinent version, reconcile entries and systems and refer differences to flag/RO.	View page →
Oil Record Book — Part I (Machinery Space Operations)	Operation not signed by the officer in charge, or completed page not signed by the Master	PSC deficiency, possible detention	View page →
Sludge Management	Sludge balance with a large, unexplained variance	An unexplained variance requiring clarification, with possible follow-up on operations and discharges Weekly C11 inventory; additional SMS balances and reconciliation with fuel consumption	View page →
Bilge Water	Confusing functional testing with alarm calibration	Equipment response may appear correct without a documented check of measurement accuracy Check functional testing/maintenance separately from the calibration certificate; use the applicable interval or the manufacturer’s shorter interval	View page →
Garbage Record Book	Confusing the Garbage Management Plan with the Garbage Record Book	The plan’s scope may be applied to the book and a required document omitted Check regulations 10.2 and 10.3 separately, including thresholds, ship branch and any formally granted waiver	View page →
Incinerator	Banning PVC in every case or accepting it as generic plastic	The selected route may be inconsistent with the incinerator’s type approval Check the appropriate IMO type approval for PVC and the manual’s limits; do not infer acceptability from the material alone	View page →
Ballast Water	Choose D-1 unilaterally after a failure	The measure may not be acceptable to the State receiving the ballast water. Follow the BWMP and agree the contingency with the relevant authorities before discharge.	View page →
Fuel Changeover	Calculating the switch for one line instead of the system	Fuel above the limit may remain in parts of the system at ECA entry Use actual system volumes, recirculation and operating conditions in the ship’s procedure; verify complete flushing	View page →
MARPOL Annex VI	Omitting the ODS list, Record Book or required events	The documentation does not reconstruct the required equipment, movements and releases Check regulation 6.1 scope, the 12.5 list and 12.6 rechargeable-system book; promptly record 12.7 events in kg	View page →
Managing a Non-Conformity (NC)	NC closed without verifying the effectiveness of the action	The root cause remains and the NC recurs (repeat NC)	View page →
Reporting a Near Miss	Punitive culture towards those who report	The reporting rate collapses and useful information is lost	View page →
Fire Drill and Fire Safety	Drill conducted as a simple announcement, without practical use of the equipment	The crew does not gain real familiarity with emergency procedures	View page →
ECDIS (Electronic Chart Display and Information System)	ENCs not updated or subscription expired	Navigation with outdated chart data, PSC deficiency	View page →
Crew Familiarisation and Training	Signature without checking understanding	Nominal preparation only	View page →
Musters and Abandon Ship Drill	Emergency duties not understood before sailing or onboard training later than two weeks	PSC deficiency, real risk in the event of an emergency before familiarization is completed	View page →
Managing Deficiencies	Rectifying the defect without assessing follow-up under the SMS	Causes or systemic problems may remain unexamined and contribute to recurrence Assess each finding under SMS procedure and link significant, systemic or recurring ones to NC/CAPA; do not automatically classify every shortcoming as ISM	View page →
Communicating with the PSCO	Memorised answers without understanding assigned duties	The answer may not reflect ability to perform the requested operation Prepare crew to explain and demonstrate their own procedures; clarify questions without coaching uniform answers	View page →
Enclosed Space Entry	Entry without instrumental verification of the atmosphere, relying only on the visual appearance of the space	An oxygen-deficient or toxic atmosphere goes undetected, a mortal risk Test the atmosphere before entry with suitable, calibrated instruments under the procedure; check gases identified by the risk assessment	View page →
COLREG in Practice	Writing Every ship under way as the general scope, confusing heading and track under Rule 10, or describing MASS as still expected in May 2026.	Incorrect operational decision or regulatory status	View page →
Bridge Resource Management (BRM)	Tasks not explicitly assigned during critical phases, with overlaps or gaps in responsibility	No one monitors a critical aspect, assuming someone else is handling it	View page →
Planned Maintenance System (PMS) and Auxiliary Machinery	Closing a job with a generic statement and no outcome.	Completed work, a failed test and an open defect become indistinguishable.	View page →
Tail Shaft Survey	Use fluid analysis alone to close the survey	Condition of seals, bearings and required surfaces remains unverified	View page →
Intermediate Survey	Schedule IOPP at month 30 between the windows	Attendance may be arranged outside the eligible window. Select and record three months before or after the certificate’s second or third anniversary.	View page →
EEXI and Engine Power Limitation (EPL)	Using the power reserve to recover commercial delays.	Use outside the safety purposes provided for override.	View page →
Sewage Management	Reading “at least 12” instead of “more than 12 nautical miles”	The selected position may not meet the regulation 11.1.1 condition for untreated sewage Check more than 12 nautical miles from nearest land and the other applicable conditions, with an operational margin	View page →
Bunker Delivery Note	Sampling LNG as conventional fuel	A sampling procedure inapplicable to the 18.5.2 branch is used Identify gas/low-flashpoint fuel first and use its data/declaration; do not impose the excluded conventional 18.8.1 sample	View page →
Handling Seafarer Complaints (MLC 2006)	Complaint procedure not provided or not clearly explained to the seafarer on joining	Seafarer unaware of their rights and the complaint procedure, MLC deficiency at inspection	View page →
Permit to Work System	Hot work permit renewed without a new atmosphere test if the work extends beyond the initial validity	Risk conditions not updated, possible accident with an atmosphere that has changed in the meantime	View page →
Ship Security Plan and the ISPS Code	SSO lacks a VI/5 CoP valid under Administration and flag rules	Clear ground for a more detailed security examination	View page →
Life-Saving Appliances: Liferafts, EPIRB and SART	Applicable liferaft servicing interval exceeded	Serious deficiency, possible detention	View page →
USCG Port State Control	Confusing an eligible flag with a QUALSHIP 21-enrolled vessel	Incentives or boarding expectations are applied when unavailable Check the flag list and the vessel’s enrollment confirmation separately	View page →
Tokyo MOU: Regional Specificities	Applying Paris MoU profiles and priorities in Tokyo MoU	Preparation is not calibrated to the competent regime Consult current Tokyo MoU APCIS, NIR and publications	View page →
Ro-Ro Cargo Securing	Securing calculated without relevant data and method or disregarding the CSM	Holding capacity not justified for the actual configuration Stop, verify method and competence and obtain the required checks and acceptance/approval	View page →
Reefer Container Monitoring	Confusing set point, air temperature and product temperature	The deviation is interpreted using the wrong quantity Identify the parameter, sensor and units and compare them with the relevant instructions	View page →
Managing Cargo Claims	Unqualified bill despite apparent defects	It may be prima facie evidence of receipt as described and materially restrict contrary evidence, especially against a lawful third-party holder Enter factual, specific and evidenced reservations	View page →
Passage Planning in Polar Waters (Polar Code)	Applying one date to every added ship	Requirement applied early or deadline missed	View page →
Electronic Navigation and GNSS Resilience	Promising accurate position with L1/L2/L5 during complete interference or making multi-band/RAIM universally mandatory.	Incorrect operational decision or regulatory status	View page →
VTS Traffic Management	Treating every VTS message as a binding order or, conversely, reducing every instruction to a mere recommendation.	Incorrect operational decision or regulatory status	View page →
Boiler Operations	Repeated resets after flame failure without assessing the fault and restart conditions	Fuel accumulation or recurrence of the abnormality, with furnace risk	View page →
Refrigeration Plant	Adding refrigerant because the room does not cool, without establishing the fault.	The cause may remain unresolved and an incorrect charge may worsen operation.	View page →
Operational Energy Efficiency in the Engine Room	Main engine operated at very low loads for long periods without assessing consumption, conditions and maker limits	Engine performance or condition may deteriorate; the trend alone does not explain annual CII	View page →
Anchor and Chain Cable Survey	Use an average of several links to assess the most worn point.	A local defect may be concealed and the length remain in service without proper assessment. Record the two perpendicular readings in the same most worn section, identifying the location.	View page →
Cargo Hold Survey for Bulk Carriers (ESP)	Closing access before agreed close-up examination and measurements	Examination may remain incomplete and access may need reinstating. Plan examination, UTM and work together; remove access after necessary checks.	View page →
Shipyard Waste Management during Dry Dock	Classification by name	Wrong code and destination. Use composition, characterization and local criteria	View page →
Safety Construction, Equipment and Radio Certificate	Use the Radio date to close Construction and Equipment	Other scopes may lack due examinations or endorsements. Connect each scope with its pertinent survey, report and endorsement, including in the combined certificate.	View page →
ISPS Certification (International Ship Security Certificate)	Plan the intermediate verification from final expiry alone	The required window or endorsement may be missed and the certificate may lose validity. Read ISSC dates and endorsements and arrange verification and endorsement with flag/RSO within the pertinent limits.	View page →
MLC Certification (Maritime Labour Certificate and DMLC)	Replace Part II with a revision not managed with the issuer	Certified documentation and actual measures may diverge without the required assessment. Compare change and practice, follow the flag/RO process and retain the certified version and revision outcome.	View page →
Ballast Water Management Convention In Depth	Using type approval as the only evidence of onboard commissioning.	Evidence of correct installation and testing on the ship is missing.	View page →
Biofouling Management	Requiring a certified in-water cleaning service or claiming formal IMO compliance without an identified scheme.	Non-compliant decision or treatment	View page →
Underwater Radiated Noise (URN)	Writing EBP until 2026, possible extension, or turning the extension into a mandatory obligation.	Non-compliant decision or treatment	View page →
Anti-Fouling Systems	Avoid equating “no dry-docking since 2023” with an exception for an ordinary ship, confusing documentary thresholds with freedom of use, renewing a system with only an internal entry, or treating flag notification as an automatic extension.	See the linked page for conditions, consequences and preventive measures.	View page →
VOC Management Plan	Generic plan without COW or a responsible person	The instructions omit a relevant operation or do not identify who implements them. Use the approved ship-specific plan with the four 15.6 components and relevant COW instructions.	View page →
Management of Change (MoC)	Internal approval without checking statutory limits	Inadmissible activity despite a MoC	View page →
Dangerous Goods Manifest and Notification to Port Authorities	Manifest compiled on the basis of initial declarations without being updated after changes to the stowage plan	Incorrect information on the actual position of the dangerous goods in an emergency	View page →
Lithium Batteries: Thermal Runaway and Fire Response on Board	Universal agent/strategy	Response conflicts with stowage or ship	View page →
IMDG Training and Crew Education	Shore-based Chapter 1.3 training and shipboard competence requirements not distinguished	The wrong legal basis and training path are assigned to personnel	View page →
Watertight Doors and Compartment Integrity	Door category and applicable rule not identified before setting its position at sea	A passenger-ship or category-specific provision is generalised to the wrong ship or door	View page →
Helicopter Operations and Helideck Safety	Helicopter operation conducted without dedicated firefighting personnel present during refuelling	Critical response time lost in the event of ignition during refuelling	View page →
Black Sea MOU: Regional Specificities	Using the 2025 rate as proof of stricter inspection	A descriptive figure is converted into a cause State year, numerator and denominator without inferring the cause of the rise	View page →
Indian Ocean MOU: Regional Specificities	Transferring another MoU’s profiles or priorities to IOMOU	Preparation is not calibrated to the competent Authority Check State, accepted instruments, national law and IOMOU publications	View page →
Heavy Lift Cargo and Project Cargo	Improvised onboard Annex 13 calculation	Securing not demonstrated against cargo data, structural limits or voyage conditions Use competent personnel, an appropriate method and data; complete required checks and acceptance or approval	View page →
BNWAS and Anti-Collision Alert Systems	Presenting under way and autopilot as alternative triggers or inventing a uniform IMO periodicity for end-to-end/power-failure tests.	Incorrect operational decision or regulatory status	View page →
Predictive Maintenance based on IoT Sensors	Mistaking missing or stale data for absence of anomalies	A problem may remain unobserved while the system appears normal	View page →
Boiler Water Treatment	Comparing samples from different points or methods as equivalents.	A measurement difference may be mistaken for a plant change.	View page →
Managing Shipyard Repair Contracts	Extra work performed without a traceable decision	Price, quantities and schedule impact may become disputed. Link the finding, variation and approval to the contract’s authority and process; retain the evidence.	View page →
Managing Surveys under Dual/Multiple Classification	Close both classes using only one status record	A condition or deadline of the other Society may remain open without follow-up. Compare both status records and obtain confirmation from each Society of credit, closure and document updates.	View page →
Statement of Compliance for Ships in Temporary Lay-up	Treat the lay-up document as suspension of every deadline	Surveys or certificates may expire without their effects being recorded in the file. Read the document’s issuer, scope and conditions and agree in writing the treatment of class and each affected certificate.	View page →
Digitalization of Statutory Certificates	Present a scan as an issued electronic certificate	The document may not support authentication or establish integrity and validity under the approved system. Retrieve the issuer’s document and check signature, identifier and authenticity/validity using onboard instructions.	View page →
Onboard Carbon Capture and Storage (OCCS)	Calling OCCS a lower-intensity energy source or promising settled future accounting.	Non-compliant decision or treatment	View page →
Shore Power and Cold Ironing (Onshore Power Supply)	Conflating AFIR and FuelEU	Separate infrastructure duties, ship duties and availability at the individual quay.	View page →
Wind-Assisted Propulsion Systems (WAPS)	Saving transferred from another ship	Unreliable business case	View page →
Dangerous Solid Bulk Cargoes: the IMSBC Code, Liquefaction and Self-Heating	Doubt about the shipper's moisture-content certificate treated as resolved by a shipboard indication	Cargo with moisture above the TML loaded without the risk being detected	View page →
MARPOL Annex III: Harmful Substances Carried in Packaged Form	'MARINE POLLUTANT' marking not applied because it is considered redundant relative to the primary IMDG class labelling	Non-compliance with MARPOL Annex III even when the IMDG safety classification is correct	View page →
Polar Waters Discharges	Avoid measuring from ice instead of also from land, equating STP certification with discharge approval, carrying an HFO waiver into another Party’s waters, or treating low-sulphur fuel as automatically outside the HFO definition.	See the linked page for conditions, consequences and preventive measures.	View page →
Contractor and External Supplier Management	Supplier controls inadequate for the service or SMS	Competence, approvals or safety not demonstrated; possible NC	View page →
Whistleblowing and Anonymous Reporting of Non-Conformities	Anonymity and confidentiality treated as synonyms or universal MLC duties	Incorrect expectations and legal basis	View page →
Immersion Suits and Thermal Protection	Immersion suits counted from the number of lifeboats on a cargo ship, where the criterion is per person	Fewer suits than persons embarked, with the shortfall never showing up in any count	View page →
Fixed Firefighting Systems: CO2 and Water Mist	CO2 system dosing not re-verified after structural modifications to the protected space	Insufficient CO2 concentration for effective extinguishing in the modified space	View page →
Means of Escape and Emergency Escape Routes	Means of escape from Category A machinery spaces verified only for their formal existence, without verifying the actual independence of the two routes	Both means of escape potentially compromised by the same event (e.g. a fire blocking a single common route)	View page →
Managing an Appeal against a Detention	Sending the appeal only to the PSCO without checking the competent body	The submission may not initiate the prescribed remedy while the deadline continues to run Identify the recipient, form, deadline and standing from the notice and national procedure; retain proof of filing	View page →
Coordination between Flag State and PSC	Sending inconsistent accounts of the same finding to flag, RO and port State	Work or testing may not address the authority’s request and verification remains incomplete Use the same PSC report, link each deficiency to an owner, action and evidence, and retain requests and confirmations	View page →
Break Bulk Cargo: Stowage, Dunnage and Damage Prevention	Stowage planning without reliable and verified weight, dimensions and centre-of-gravity data for the items concerned	Cargo instability and risk of damage during transport Plan by item or homogeneous group using verified data and arrangements, without automatically transferring standardised-cargo patterns	View page →
Charter Parties and Cargo-Specific Clauses	Voyage and time charter confused	Wrong economic mechanism Identify actual hire/off-hire and laytime clauses	View page →
Icebreaker-Assisted Convoy Navigation	Saying convoy command replaces the Master's independent safety judgement or using seasonal statistics as an operational requirement.	Incorrect operational decision or regulatory status	View page →
Datum Shift and Chart Reference in ECDIS	Describing every datum uncertainty as GPS/ECDIS error, checking datum notes alone, or applying an unauthorised manual offset.	Incorrect operational decision or regulatory status	View page →
Integrated Automation Systems and Unmanned Machinery Space (UMS)	Deciding on UMS solely because the panel shows no alarms	Defects, inhibited safety functions or work may remain invisible	View page →
Digital Twin for the Engine Room	Investment without checking the data needed for the use case	Simulation model fed by insufficient or low-quality data, with unreliable predictions	View page →
Managing Post-Repair Warranties (Warranty Claims)	Recording only sending when receipt is required	Receipt within the deadline may remain unsubstantiated, weakening the claim. Check the contractual recipient, channel and deadline and retain the required evidence of receipt.	View page →
Dry Dock Scheduling for Sister Ships (Sister Ship Scheduling)	Treating a finding on the first ship as already verified on the second	Unnecessary work may be ordered or the actual defect left unchecked. Compare configuration and condition; record verification and outcome on each ship before confirming its work.	View page →
Interim Certificates	Apply SMC duration and extension rules to every interim	Definitive verification may be planned beyond the permitted ISSC or MLC validity. Identify each document, record its instrument’s duration and request only permitted extensions without treating them as automatic.	View page →
Coordination between Class Surveys and Statutory Surveys (RO)	HSSC used for class	Wrong window Consult Rules and survey status separately	View page →
Methanol and Ammonia Bunkering: Infrastructure and Real Cases	Citing 48/200 ports, most ports or first ships 2026–2027 without primary source and method.	Non-compliant decision or treatment	View page →
Just Transition and the Social Impact of Decarbonization	Identical training for everyone	Gaps in critical roles	View page →
Review of the EU MRV Framework in Light of the EU ETS	Wrong COM number	Source concerns a different ETS measure	View page →
IMO DCS Transport Work	Delete an incomplete period	The report loses continuity and the gap cannot be verified. Recover and reconcile evidence, documenting estimates and residual gaps for the verifier.	View page →
Prevention of Violence and Harassment Onboard	PSSR course delivered from 2026 without the new competence	Training does not meet the amended table	View page →
Master's Authority and Safety Culture	Master's overriding authority documented in the SMS but not concretely supported when the safety decision carries a commercial cost	Erosion of the Master's trust in the system and implicit pressure to favour commercial needs	View page →
Ro-Ro and Vehicle Spaces: New Fire Detection and Protection Requirements (2026)	Keel-laying date not verified to determine applicability of the new 2026 requirements	Detection system design not compliant with the requirements applicable to the ship	View page →
Shipboard Lifting Appliances: The New SOLAS Regulation II-1/3-13 Regime	Cargo cranes left out of the survey, on the view that Regulation II-1/3-13 covers only non-commercial appliances	In-scope appliances are omitted from controls, documentation and planning.	View page →
Mediterranean MOU: Regional Specificities	Using the source’s 20% as a verified increase in the 2024 detention rate	Counts and rates are confused and the 157→196 discrepancy is hidden Quote 196 detentions and 5,993 inspections; distinguish the approximately 3.27% rate and the 157→196 comparison, flagging the inconsistent 20% in the narrative	View page →
Bulk Carriers: PSC Risk Profile and Recurring Deficiencies	Assigning the aggregated DNV ranking to bulk carriers alone	Operational priorities are not supported by the quoted aggregate Name container, bulk carrier and general cargo together and use ship-specific data for priorities	View page →
BLU Code: Safety in the Loading and Unloading of Bulk Carriers	Using the information exchange instead of the agreed plan and checklist.	Sequence, limits and safety conditions have not been agreed between ship and terminal. Keep the three documents distinct and complete agreement on the plan, checklist and communications before starting.	View page →
Mandatory Reporting of Containers Lost at Sea (SOLAS 2026)	Observation automatically sent to flag State as SOLAS duty	Recipients for the two events are confused Use nearest coastal State and ships in vicinity for observation	View page →
Cargo Record Book (Record Book for Noxious Liquid Substances)	Prewash not compliant with the P&A Manual	Annex II breach Follow the approved Manual and authorised surveyor	View page →
Cargo Securing Manual and Cargo Lashing	Cargo Securing Manual not updated after changes to the securing equipment	The manual no longer reflects the ship's actual securing capacity Revise the CSM for new or alternative device types and follow the applicable Administration revision/approval procedure	View page →
Draft Survey and Determining Cargo Quantity	Confusing the ship’s constant with variable ballast and consumables	Incorrect non-cargo deductions distort the cargo quantity Measure ballast and consumables at initial and final surveys and check lightship and constant separately	View page →
IMDG Code — Carriage of Dangerous Goods in Packaged Form	Using 41-22 as a current alternative in 2026	Entries and instructions do not match the edition applicable to the shipment Check the applicable edition and official corrections; use 42-24 in 2026	View page →
Loading/Discharging Plan	Ship/shore plan applied outside its scope	Wrong operating regime Identify ship, cargo and applicable basis	View page →
Tank Cleaning	Using the P&A Manual as the sole safety guide or guarantee of next-cargo purity	Washing risks or residual contamination are not assessed Separate the MARPOL check, risk assessment and safety instructions, and next-cargo criteria and checks	View page →
Simulator Training: the Ongoing STCW Review	Presenting 37 States, three months and specific Regulations as a Committee outcome without the exact primary document and paragraph.	Incorrect operational decision or regulatory status	View page →
MASS Code: the New IMO Framework for Autonomous Ships	Saying entered into force, inventing a two-year voluntary introduction period, treating EBP as begun, or turning 2030/2032 into legal certainty.	Incorrect operational decision or regulatory status	View page →
Methanol Engines: Reliability and Spare Parts Management in a Still-Young Technology	Order a seal by size alone, without checking its material and revision for the methanol installation	An incompatible or unusable spare, with leakage risk and delayed restoration	View page →
Fire Safety of Onboard Battery Rooms (BESS)	Treating the BESS as safe after electrical isolation or disappearance of flames	The thermal process, gases and residual energy may keep the hazard active	View page →
Hong Kong Convention: Inventory of Hazardous Materials and Green Passport	Treating a Green Passport as automatic evidence of IHM compliance	Inventory and certification not evidenced. Check content, updates and acceptance under the applicable regime	View page →
Next-Generation Coating: Planning the Dry Dock Choice	Choose a coating without comparing it with the ship’s actual idle periods and speeds.	The system may operate outside intended conditions, with fouling accumulation and additional maintenance. Compare operating data, stated limits and required maintenance before accepting the specification.	View page →
Hot Work Permit at the Shipyard: Ship-Dock Coordination	Start work with ship and yard permits describing different conditions.	A team may start while isolations or simultaneous activities make the area unsuitable. Align task, location, validity, isolations and conflicting work at the permit control point before starting.	View page →
Change of Flag and the Shadow Fleet: What Changes for Surveys and Certificates	Use printed expiry as a guarantee after a flag transfer	A certificate that ceased to be valid on transfer may be presented. Check each instrument’s provision, document any permitted transition and obtain the new certificate when required.	View page →
Coordination between the HSSC Cycle and SIRE 2.0 Vetting Inspections	Prepare every crew member on the entire Question Library	Preparation may overlook familiarity with the procedures and equipment used in actual duties. Use the applicable Library to prepare each role and check HVPQ/PIQ particulars without assuming advance knowledge of the assigned CVIQ.	View page →
CII: 2027-2030 Reduction Factors and New SEEMP Granularity	Applying Z to the previous year’s result	Required CII is calculated from the wrong base	View page →
Alternative Fuels and Operational Readiness	Applying IGF Code compliance indiscriminately to ammonia, hydrogen, methanol and LPG.	Non-compliant decision or treatment	View page →
CII (Carbon Intensity Indicator)	Treating a single D as three consecutive D ratings	The corrective-action obligation is misstated	View page →
EU ETS and FuelEU Maritime	Writing all MRV ships enter ETS in 2027, one ≥5,000 scope, or 100% of every global emission.	Non-compliant decision or treatment	View page →
SEEMP Part II and Part III	Conflating Parts II and III	DCS methodology and CII planning are not checked against their respective scopes	View page →
Environmental Vetting and GHG Rating	Claiming automatic exclusion by BHP/Vale/Cargill/Rio Tinto or merging GHG, Safety Score and age trigger.	Non-compliant decision or treatment	View page →
Carriage of Radioactive Materials: IMDG Class 7 and the INF Code	Port-call and transit regimes treated as identical	Route requirements omitted or approvals sought without checking their basis	View page →
Dangerous Goods in Holds on Non-Containerised General Cargo Ships	Mode-specific stowage and segregation provisions not applied to conventional non-containerised cargo	Physically insufficient segregation distance in the hold	View page →
CTU Code: Packing and Stowage of Cargo Transport Units	CTU filled without a prior check of the structural integrity of the unit	Risk of loss of tightness or structural failure during transport	View page →
EmS Guide and MFAG: Responding to Emergencies Involving Dangerous Goods	EmS Guide or MFAG on board in an edition not consistent with the IMDG edition applied to the cargo	Absence of emergency procedures for the new entries introduced by the latest amendment	View page →
IBC Code and Operations on Chemical Tankers	P&A always attributed to class	Approval authority misstated	View page →
Liquefied Gases and Operational Notes on the IGC Code	Tank cooldown carried out too quickly relative to the prescribed cooling curve	Risk of thermal shock and structural damage to the containment system	View page →
Safe Return to Port: The Design Principle for Passenger Ships	Treating SRtP system redundancy as purely a design feature, without verifying its operational upkeep over time	Progressive degradation of the actual return-to-port capability compared with what was foreseen at the design stage	View page →
Passenger Musters at Embarkation: Before Departure, No Longer Within 24 Hours	Still applying, out of habit or outdated training, the old rule of a muster 'within 24 hours of departure'	Non-compliance with SOLAS III/19 as amended from 2015, with passengers lacking safety instructions for a stretch of the voyage	View page →
Damage Stability of Ro-Ro Passenger Ships (SOLAS 2020)	Determining the regime from keel date alone or from a sister ship’s date	A vessel caught by the delivery trigger or another SOLAS 2020 trigger may be classified incorrectly	View page →
Managing a Gastrointestinal Outbreak on Board	Waiting for a percentage threshold before applying the plan’s measures to an individual AGE case	Delayed identification, management and containment	View page →
SAR Cooperation Plan on Passenger Ships	SAR cooperation plan developed only once and never updated afterward	Plan no longer consistent with the actual operating area or the SAR services actually available	View page →
Persons with Reduced Mobility: Accessibility on Board	Extending the EAA indiscriminately to every digital system and onboard self-service terminal	The compliance perimeter exceeds the Directive’s scope	View page →
Evacuation Analysis on Passenger Ships: Simplified and Advanced Method	Using the simplified method for complex ship configurations in which its underlying assumptions no longer hold	Evacuation analysis not representative of actual behaviour in an emergency	View page →
Passenger Ship Safety Certificate: The Twelve-Month Renewal Survey Regime	PSSC renewal survey planned last-minute, without integration into the ship's general operating calendar	Operational pressure and risk of impact on scheduled passenger service	View page →
Gangway Operations	Material errors include treating 600 mm as a universal operational clearance; linking a net only to water; assigning PPE an independent universal date; imposing a security configuration absent from the SSP; or treating ladder and winch as one lifting appliance.	See the linked page for conditions, consequences and preventive measures.	View page →
Tender Operations: Service Boats for Passenger Transfer	Presenting the MSC.1/Circ.1417 risk assessment and log as universal obligations	Recommendatory guidance is converted into a Convention requirement beyond its scope	View page →
Passenger Accounting: The Accuracy of the Roll-Call after Costa Concordia	Counting of those present at assembly stations left to individual initiative, without a written and assigned procedure	As in the Costa Concordia case, inability to establish with certainty who is actually present or missing	View page →
Crowd Management: Managing the Flow to Assembly Stations	Changing the route without informing connected positions.	Conflicting directions and groups converging on the same point.	View page →
Cabin Safety: Stateroom Security Requirements under the CVSSA	Ineffective visual identification or alternative means lacking documented review	Possible USCG finding: assess the functional requirement and installed solution	View page →
The Onboard Medical Centre: Between MLC and Voluntary Standards	Presenting ACEP as a general legal requirement	Confusion between binding requirements and a voluntary standard	View page →
Turnaround Operations	Recurring errors are leaving interfaces unassigned or imposing names and controls absent from the SMS. Identify the responsible person, stop-work authority and the risk criterion actually applicable.	See the linked page for conditions, consequences and preventive measures.	View page →
North-East Atlantic ECA	Correctly deferring SOx/PM but overlooking NOx	A subject engine may be prepared only for 2028 Separate the calendars and check applicable Tier III from 1 September 2027; the 14.7 suspension concerns sulphur	View page →
Integrated Bilge Water Treatment System: Current Guidance and Draft Regulation 12B	Apply draft regulation 12B already	Documents or criteria not yet applicable may be demanded or used. Distinguish current requirements, guidance and the text awaiting adoption.	View page →
Marine Plastic Strategy and Pellet Code	Wait until 2030 for the plastics prohibition	An already applicable Annex V duty is deferred. Apply the prohibition and limited regulation 7 exceptions within their current scope.	View page →
NOx Technical Code: Recertification, Multiple Profiles and the Ammonia/Hydrogen Draft	Using Engine Family instead of Engine Group under section 7.2	Certification may be prepared using a procedure not permitted for a family Check individual-engine or Group status represented by the parent and agree the plan with the Administration	View page →
New 2026 ECAs: Canadian Arctic and Norwegian Sea	Merging NOx in 2026 and SOx/PM in 2027, or using the North-East Atlantic calendar	The voyage or engine configuration may be prepared against the wrong commencement date Connect area, voyage date and individual engine with the separate calendars; do not wait until 2027 for applicable Tier III	View page →
SOPEP — Shipboard Oil Pollution Emergency Plan	Emergency contacts not updated	Delayed notification in a real spill Keep and check the latest IMO list with published updates; update ship, flag, Company and agent contacts separately whenever they change	View page →
Crew Fatigue: The IMO 2026-2027 Review Process	Formally tidy but inaccurate records	Fatigue and breaches remain hidden	View page →
Corrective and Preventive Action (CAPA)	Corrective action addressing the symptom, not the root cause	The NC recurs in similar form	View page →
Cyber Risk Management in the SMS (MSC.428(98))	Cyber risk managed as a separate IT matter, not integrated into the SMS's general risk assessment	Lack of integrated documentary evidence in the event of an audit, despite the existence of technical IT measures	View page →
Designated Person Ashore (DPA)	DPA without real access to senior management	Ineffective escalation and possible NC	View page →
Document of Compliance (DOC) and Safety Management Certificate (SMC)	Confusing DOC annual and SMC intermediate checks	Missed verifications and validity not assured; possible enforcement	View page →
Emergency Preparedness and Contingency Plan	Generic plan not aligned with the ship's profile	Roles, resources and actions do not match the actual scenario	View page →
Crew Familiarisation and Training	Signature without checking understanding	Nominal preparation only	View page →
Internal SMS Audit	Independence not assessed and no justification of a §12.5 exception	Objectivity not demonstrated	View page →
Management Review	Review without evidence of evaluation	SMS effectiveness not demonstrated	View page →
Autonomous Ships (MASS): the Company's Responsibility under the SMS	MASS responsibility allocated generically to the DPA	Monitoring and operational control become confused	View page →
Pilot Transfer Arrangements: The New SOLAS V/23 Performance Standard	New construction for delivery from 2028 planned without specifying compliance with the new performance standard to the shipyard	Devices compliant only with the old version of Regulation V/23, to be upgraded later at additional cost	View page →
Ship Fuel Safety: Flashpoint Declaration	Bunkering started without having received the supplier's signed declaration on the flashpoint	Non-compliance with the new SOLAS requirement and risk of fuel with an unverified flashpoint on board	View page →
Emergency Generator Test	Test limited to the start alone, without verifying the actual load pick-up	Hidden faults only emerge during a real emergency or a thorough inspection	View page →
GMDSS (Global Maritime Distress and Safety System)	Radio tests performed at a supposedly universal interval or by a universal method	Test inconsistent with applicable instructions or inappropriate on-air call	View page →
Lifeboat Inspection (Inspection and Maintenance of Life-Saving Boats)	Crew on board during under-load release tests not specifically established as safe	Risk of serious or fatal injury in the event of a hook malfunction	View page →
Passage Planning	Passage plan drawn up only for the open-sea route, not berth-to-berth	Critical port manoeuvring phases not adequately planned	View page →
Fraudulent Certificates and Registrations: Paris MoU Guidance under Development	Using only contacts on the suspect document to confirm it	The reply may come from the same unverified party and the doubt remains unresolved Obtain independent official contacts for the flag and authorized issuer/RO, and retain provenance and the response	View page →
Pre-PSC Checklist	Checklist applied only when an inspection is considered 'likely'	Pre-existing deficiencies remain undetected at port calls perceived as low risk Integrate review into port-call preparation under the Company SMS rather than relying only on inspection likelihood; tests and maintenance follow their own due dates	View page →
Concentrated Inspection Campaigns (CIC)	No specific preparation ahead of an announced CIC	A more thorough inspection on the topic catches the crew unprepared Monitor the CIC calendar and start targeted preparation several months in advance	View page →
Detention and Banning	Treating repair or a class report as authority release	The ship may plan departure while detention or a separate ban remains in force Retain the port-State decision and check refusal-of-access lifting conditions separately	View page →
Documentation Required on Board	On-board certificate copy not updated after renewal or audit	Inconsistent documentation during inspection Replace the copy promptly and verify validity and endorsements	View page →
Ship Risk Profile and New Inspection Regime (NIR)	Using a Paris MoU profile or window for a Tokyo MoU call	Priority and expected date may be wrong Consult each regional NIR separately: THETIS for Paris MoU and APCIS for Tokyo MoU	View page →
VDES and NAVDAT: the Next Generation of Digital Maritime Communications	Equipping for every RMSS or accepting an MSI gap based on dissemination rules	Incorrect configuration or compliance assessment	View page →
Next-Generation ECDIS: the S-100 Framework	Saying no mandatory date fixed, presenting S-57 as the sole future basis, or turning 2029 into mandatory retrofit of every existing ECDIS.	Incorrect operational decision or regulatory status	View page →
Anchoring and Anchor Watch	Chain paid out according to a fixed generic rule, without considering forecast weather/sea conditions	Insufficient anchor holding if conditions deteriorate	View page →
Pilotage and Under Keel Clearance in Restricted Areas	Attributing a simplified UKC formula directly to SOLAS V/34 or treating the pilot as a transfer of ship responsibility.	Incorrect operational decision or regulatory status	View page →
VDR (Voyage Data Recorder)	Annual performance test not carried out or overdue	PSC deficiency, risk that the VDR will not function correctly when needed	View page →
Navigation in Restricted Visibility	Reducing Rule 19(d) to do not alter towards a contact forward of the beam, omitting the second branch, or treating darkness as a standalone restricted-visibility category.	Incorrect operational decision or regulatory status	View page →
Watchkeeping	Accepting an incomplete handover or treating the scheduled time as transfer of the watch.	Responsibility and hazards needing follow-up remain uncertain.	View page →
Ammonia Engines: Safety and Reliability of the First Units in Service	Using odour or absence of a single alarm to declare a space safe	Incomplete exposure assessment; use the prescribed detection, access conditions and response.	View page →
Bunkering Operations and Fuel Quality Control	Treating a signed BDN and checklist as sufficient control of the transfer	Levels or anomalies left unattended, with overfilling and spill risk	View page →
Cyber Risk Management of Automation Systems	Assuming OT is secure because it does not directly use the Internet	Access through connected networks, media or maintenance is left outside the assessment	View page →
Blackout and Failure Management	Reporting “fully restored” solely because the emergency generator starts.	The bridge and watch may rely on propulsion, steering or auxiliaries that remain unavailable.	View page →
Critical Spare Parts Management	Critical spares list not updated after changes to the identified critical equipment	Missing spares for equipment recently classified as critical	View page →
Fire Pumps and Fixed Systems in the Engine Room	Testing the emergency pump without verifying its power and pipework configuration	The recorded start does not demonstrate availability of the intended emergency arrangement	View page →
Purifiers and Separators (Fuel Oil / Lube Oil Purifiers)	Changing settings without fuel data and maker instructions	Ineffective or unstable separation	View page →
Remote Inspection Techniques (RIT): Drone and ROV Inspections	Lose the finding location	The image cannot support relocation and verification of the defect; link the file, compartment and structural item.	View page →
Bottom Survey and In-Water Survey (IWS)	Booking a method without confirming eligibility	Completed inspection may not satisfy the survey due. Establish regime, items, conditions and acceptance before appointment.	View page →
Coating and PSPC (Performance Standard for Protective Coatings)	Recoating without checking preparation and compatibility	The coating may detach or deteriorate prematurely. Agree preparation and a compatible system; verify them before application.	View page →
Dry Dock Entry Planning	Cargo regime used for passenger ship	Wrong due date or method	View page →
Thickness Measurement (Ultrasonic Thickness Measurement, UTM)	Reading without member/location	It cannot be repeated or compared with drawings or a later survey. Use consistent structural references and point mapping.	View page →
Survey in Dry Dock	Treating Special Survey and statutory renewals as one acceptance	A certificate or condition may remain unverified	View page →
Rudder and Sea Chests (Sea Chests and Sea Valves)	Record a rudder clearance without location and acceptance reference.	The reading cannot be assessed or compared with the bearing history. Identify the bearing, method, value and applicable limit in the report.	View page →
The IP Code: the Industrial Personnel Safety Certificate	Count only IP to determine applicability	The aggregate threshold may be exceeded without identifying the required regime before carriage. Add IP, special personnel and passengers, retain the 12-passenger limit and check the ship’s scope and documents.	View page →
Annual Survey	Prepare only documents	Item condition and necessary tests may remain unverified. Agree items, access and tests and connect results with the documented condition.	View page →
Condition of Class and Recommendations	Close solely on the yard’s statement	The condition may remain open with class and pass its deadline. Follow required verification and retain Society confirmation and updated status before recording closure.	View page →
Harmonized System of Survey and Certification (HSSC)	Use only printed expiry	An annual, intermediate or periodical survey may remain incomplete within its window. Record the certificate, anniversary, survey type, window and separate outcome.	View page →
International Load Line Certificate	Check only assigned freeboard and expiry	Ineffective fittings or missing endorsements may remain undetected. Compare marks, conditions of assignment, fitting condition and surveys/endorsements.	View page →
Remote Survey Guidance: Remote Survey, ISM Audits and ISPS Verifications	Treat an eligible portion as a fully remote survey	Required physical checks may be omitted and the survey may remain incomplete. Assess and plan each item according to survey type and ship conditions; obtain competent acceptance and retain the required in-person completion.	View page →
Renewal Survey and Certificate Renewal	Confuse booking, completed survey and issued certificate	The ship may lack a valid document despite recorded work or an appointment. Follow coverage, report, decision and final document before treating renewal as closed.	View page →
Tonnage Certificate and IMO Number	Use GT as weight or deadweight	Threshold or document comparison may use an irrelevant value. Distinguish certified GT/NT from displacement and deadweight and use the required measure.	View page →
IMO Net-Zero Framework	Writing MEPC 84 approved detailed implementation guidelines or prices have been set.	Non-compliant decision or treatment	View page →

Every operational page has a recurring-mistakes section: this page reproduces one entry and links to the full discussion.

Entries aligned with the recurring-mistakes sections of the linked pages on 16 September 2026. The Consequence / prevention column describes effects or preventive measures according to the source; this is not a statistical ranking.

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