Regulations, ISM, MARPOL and the MCA Oral

Prerequisites

This is the final lesson of the Officer of the Watch (Unlimited) course. You should have worked through the earlier lessons on certification routes, bridge watchkeeping, COLREGs, passage planning, radar and ECDIS, shiphandling, and emergencies and GMDSS. You should have completed, or be close to completing, your sea service, the STCW and MCA-approved training courses and the written examinations, so that you can apply for your Notice of Eligibility (NoE) and book the MCA oral.

The oral examiner expects you to know the main international conventions well enough to apply them on watch. You do not need to quote regulation numbers from memory, but you must know what each convention requires of you as OOW, what records you keep, and when to call the master.

Learning Objectives

Summarise the structure of SOLAS and the chapters most relevant to the OOW.
Explain the ISM Code, the Safety Management System, the DPA and the certificates it requires.
State the OOW's duties under MARPOL Annexes I to VI and the Ballast Water Management Convention, including record books, discharge rules and special areas.
Outline the Maritime Labour Convention, including hours of rest, and the ISPS Code.
Describe how port state control works and how to prepare for an inspection.
Explain how the MCA oral examination is booked and conducted, and prepare a strategy for answering questions.

The Framework: IMO, Flag and Port

Shipping is regulated mainly through international conventions agreed at the International Maritime Organization (IMO). A convention binds a ship through her flag state, which writes it into national law (for UK ships, through Merchant Shipping regulations and MCA notices: MSNs are mandatory, MGNs are guidance, MINs are information). Port states then check foreign ships in their ports. The "four pillars" of international maritime law are:

Convention	Purpose
SOLAS (1974, as amended)	Safety of life at sea: construction, equipment, operation
MARPOL (1973/78)	Prevention of pollution from ships
STCW (1978, as amended 2010)	Training, certification and watchkeeping standards
MLC (2006)	Seafarers' working and living conditions

Other key instruments include the COLREGs, the Load Line Convention, the Ballast Water Management Convention, and codes made mandatory through SOLAS such as the ISM Code, the ISPS Code, the IMDG Code and the Polar Code.

SOLAS

SOLAS is divided into chapters. You should know what each covers:

Chapter	Subject
I	General provisions, surveys and certificates
II-1	Construction: subdivision, stability, machinery and electrical installations
II-2	Fire protection, detection and extinction
III	Life-saving appliances and arrangements
IV	Radiocommunications (GMDSS)
V	Safety of navigation
VI	Carriage of cargoes and oil fuels
VII	Carriage of dangerous goods (IMDG Code)
VIII	Nuclear ships
IX	Management for the safe operation of ships (ISM Code)
X	Safety measures for high-speed craft
XI-1	Special measures to enhance maritime safety
XI-2	Special measures to enhance maritime security (ISPS Code)
XII	Additional safety measures for bulk carriers
XIII	Verification of compliance
XIV	Ships operating in polar waters (Polar Code)

Chapter V: the OOW's chapter

Chapter V applies to all ships on all voyages (with a few exceptions) and is the one you will be questioned on most. Key regulations:

Regulation 19: carriage requirements for shipborne navigational systems and equipment (compasses, radar, ARPA, AIS, ECDIS, BNWAS, echo sounder and others, by ship size).
Regulation 20: voyage data recorders.
Regulation 22: navigation bridge visibility.
Regulation 23: pilot transfer arrangements.
Regulation 24: use of heading and track control systems: change to manual steering in good time in areas of high traffic density, restricted visibility and other hazardous situations; test the manual steering after prolonged use of automatic steering and before entering areas where navigation demands special caution.
Regulation 25: operation of steering gear: more than one power unit in operation where navigation demands special caution.
Regulation 26: steering gear testing within 12 hours before departure, and drills every three months.
Regulation 27: nautical charts and publications kept up to date.
Regulation 28: records of navigational activities and daily reporting.
Regulations 31 and 32: danger messages (ice, derelicts, tropical storms, winds of force 10 or above without warning) and the information they must contain.
Regulation 33: obligation to assist persons in distress.
Regulation 34: safe navigation and avoidance of dangerous situations, requiring a voyage plan berth to berth (IMO Resolution A.893(21)).
Regulation 34-1: the master's discretion is not to be constrained by the owner or charterer.
Regulation 35: misuse of distress signals is prohibited.

Certificates

Know where the statutory certificates are kept: for a cargo ship these include the safety construction, equipment and radio certificates, Load Line, Tonnage, IOPP, ISPP, IAPP, IEE, Ballast Water Management, SMC, ISSC and Maritime Labour certificates, the Minimum Safe Manning Document and the Continuous Synopsis Record.

The ISM Code

Why it exists

The International Safety Management (ISM) Code was made mandatory by SOLAS Chapter IX after a series of disasters in the 1980s, notably the Herald of Free Enterprise capsize at Zeebrugge in 1987, where the inquiry found that shore management had no proper system for safety. The ISM Code makes the company (the owner or the manager who has taken responsibility for operating the ship) responsible for safety, and requires a documented Safety Management System (SMS).

The Safety Management System

The objectives of the Code are to ensure safety at sea, prevent human injury or loss of life, and avoid damage to the environment and to property. The SMS must include:

A safety and environmental protection policy.
Instructions and procedures for safe operation of ships and protection of the environment.
Defined levels of authority and lines of communication between shore and ship personnel.
Procedures for reporting accidents and non-conformities.
Procedures to prepare for and respond to emergencies.
Procedures for internal audits and management reviews.

The diagram below shows how these parts work as a continuous loop of improvement.

The ISM Safety Management System as a continuous improvement loop with the DPA at its centre

Key people

The Designated Person Ashore (DPA). Every company must appoint a person ashore with direct access to the highest level of management, to provide a link between the company and those on board, and to monitor the safety and pollution prevention aspects of each ship. As OOW, you may contact the DPA directly if you have a safety concern that is not being addressed on board.
The master. The Code requires the company to state clearly that the master has overriding authority and responsibility to make decisions on safety and pollution prevention, and to request the company's help when needed. The master also reviews the SMS and reports its deficiencies to the shore.

Certificates and audits

The company holds a Document of Compliance (DOC), issued by the flag state or a recognised organisation, valid for five years with annual verification.
Each ship holds a Safety Management Certificate (SMC), valid for five years with at least one intermediate verification (between the second and third anniversary).
Interim certificates (valid up to six months) apply to new companies and ships.
The company carries out internal audits on each ship at least once a year, and external audits are carried out by the flag state or its recognised organisation.

What the ISM Code means for the OOW

You use the SMS every day: checklists for arrival, departure, pilotage and watch handover; emergency checklists; standing orders; procedures for permits to work and enclosed spaces. The examiner may ask: "What is a non-conformity?" (a situation where objective evidence shows that a specified requirement is not met) and "What would you do if you found one?" (report it through the SMS so it can be investigated and corrected). A major non-conformity is one that poses a serious threat to safety or the environment and needs immediate corrective action. Near-miss reporting is part of the same system: reporting hazardous occurrences that did not cause harm is how the ship learns before an accident happens.

MARPOL

MARPOL has six technical annexes. The diagram below summarises what each means for the OOW.

Annex I: oil

Machinery space discharges (ships of 400 GT and above): oily water may be discharged only if the ship is proceeding en route, the mixture is processed through approved oil filtering equipment, the oil content without dilution does not exceed 15 parts per million, the equipment has an alarm and automatic stopping device, and the mixture does not come from cargo pump rooms of oil tankers or contain cargo residues. In the Antarctic area, any discharge of oil is prohibited.

Cargo area discharges (oil tankers): permitted only outside special areas, more than 50 nm from the nearest land, while proceeding en route, with an instantaneous rate of discharge not exceeding 30 litres per nautical mile, a total quantity not exceeding 1/30,000 of the cargo of which the residue formed part, and with the oil discharge monitoring and control system (ODME) operating.

Annex I special areas include the Mediterranean, Baltic, Black Sea, Red Sea, Gulfs area, Gulf of Aden, Antarctic, North West European waters, the Oman area of the Arabian Sea and Southern South African waters. Check the current list in MARPOL.

The Oil Record Book (ORB). Part I (machinery space operations) is carried by every oil tanker of 150 GT and above and every other ship of 400 GT and above. Part II (cargo and ballast operations) is carried by oil tankers. Entries are made for each operation (bunkering, transfer of sludge, discharge through the oily water separator, incineration, and so on), each entry is signed by the officer or officers in charge of the operation, and each completed page is signed by the master. The ORB is kept on board for three years after the last entry. False entries in the ORB are a criminal offence in many countries and have led to large fines and the imprisonment of officers.

SOPEP. The Shipboard Oil Pollution Emergency Plan (oil tankers of 150 GT and above, other ships of 400 GT and above) sets out what to do in a spill: reporting, steps to control the discharge, and contacts. Any spill must be reported without delay to the nearest coastal state.

Annex II: noxious liquid substances in bulk

Applies to chemical tankers. Substances are categorised X, Y, Z and Other Substances (OS) by the hazard they pose. Discharges are tightly controlled and recorded in the Cargo Record Book. The ship has a Procedures and Arrangements Manual and a Shipboard Marine Pollution Emergency Plan (SMPEP).

Annex III: harmful substances in packaged form

Packages containing marine pollutants must be marked, labelled, documented and stowed in line with the IMDG Code. The OOW on a container ship should know where the marine pollutants are stowed (from the dangerous goods manifest and stowage plan) and what to do if a package is lost overboard (report it).

Annex IV: sewage

Sewage may be discharged at more than 3 nm from land if it is comminuted and disinfected by an approved system, or at more than 12 nm if untreated, provided the ship is en route at not less than 4 knots and the discharge is at a moderate rate. An approved sewage treatment plant allows discharge closer to land. The Baltic is a special area for passenger ships. Check the current rules for your ship type and area.

Annex V: garbage

Since 2013 the discharge of all garbage into the sea is prohibited, except as specifically permitted. The table below summarises the main rules.

Key points:

Plastics are never discharged, anywhere, including synthetic ropes, fishing nets and plastic garbage bags. Cooking oil and incinerator ash are also prohibited.
Food waste may go overboard when en route and as far as practicable from land: not less than 12 nm if not comminuted, or 3 nm if comminuted to pieces of 25 mm or less. In special areas, only comminuted food waste, not less than 12 nm from land.
Ships of 12 m and over display placards explaining the rules. Ships of 100 GT and over, and ships certified to carry 15 or more persons, have a Garbage Management Plan. Ships of 400 GT and over, and ships certified to carry 15 or more persons on international voyages, keep a Garbage Record Book, retained for two years after the last entry.
Each discharge, incineration or delivery ashore is recorded with date, time, position, category and estimated amount. Accidental loss of fishing gear must also be recorded and reported.

Annex VI: air pollution

Sulphur in fuel: the global limit has been 0.50% by mass since 1 January 2020, and ships may not carry non-compliant fuel for their own use unless fitted with an approved exhaust gas cleaning system (scrubber).
In Emission Control Areas (ECAs) the limit is 0.10%. The SOx ECAs include the Baltic, the North Sea (including the English Channel), the North American and United States Caribbean areas, and from 1 May 2025 the Mediterranean. Others are being added; check the current list.
Fuel changeover: before entering an ECA the ship changes over to compliant fuel. The OOW often records the date, time and position at which the changeover started and was completed, and the volume of compliant fuel in each tank, in the logbook as the regulation requires.
NOx: engines are certified to Tier I, II or III limits; Tier III applies in NOx ECAs for ships built from the relevant dates.
Ozone-depleting substances (refrigerants) are controlled and recorded; shipboard incineration is restricted.
Energy efficiency rules (EEXI, the Carbon Intensity Indicator and the SEEMP) also sit in Annex VI.

Ballast water

Ballast water is controlled by a separate convention, the Ballast Water Management Convention (BWM, 2004), in force since September 2017, because ballast moves invasive species (such as the zebra mussel) around the world.

D-1 standard (exchange): ballast exchanged at least 200 nm from the nearest land in water at least 200 m deep, or where that is not possible, at least 50 nm from land in water 200 m deep, achieving at least 95% volumetric exchange (pumping three times the tank volume through if using the flow-through method).
D-2 standard (performance): discharge must meet limits on viable organisms, which in practice requires an approved ballast water treatment system. All ships to which the Convention applies were required to meet D-2 by 8 September 2024.
The ship carries an approved Ballast Water Management Plan and a Ballast Water Record Book, recording every uptake, treatment, exchange and discharge with positions and times.

The Maritime Labour Convention (MLC 2006)

The MLC, often called the seafarers' bill of rights, sets minimum standards for:

Minimum age (16), medical certificates and training.
Seafarer employment agreements, wages and leave.
Hours of work and rest.
Accommodation, recreational facilities, food and catering.
Medical care on board and ashore, and health and safety protection.
Repatriation, and financial security for abandonment and for death or long-term disability.
On-board and onshore complaint procedures.

Ships of 500 GT and above on international voyages carry a Maritime Labour Certificate and a Declaration of Maritime Labour Compliance (DMLC).

Hours of rest

The OOW must know the rest rules, because fatigue causes groundings and collisions, and because you will be asked. Under both MLC and STCW the minimum hours of rest are:

10 hours in any 24-hour period, and
77 hours in any 7-day period.

Rest may be divided into no more than two periods, one of which must be at least six hours long, and the interval between consecutive periods of rest must not exceed 14 hours. Musters and drills should be conducted so as to minimise disturbance. Records of hours of rest must be kept for each seafarer and must be accurate: falsified records are a serious deficiency found by port state control and a sign of a dangerous culture. The UK applies these rules through the STCW Regulations 2022 and MSN 1868. The master may suspend the schedule in an emergency affecting the safety of the ship, persons or cargo, or to help other ships in distress, but must then give compensatory rest.

The ISPS Code

The International Ship and Port Facility Security (ISPS) Code, made mandatory by SOLAS Chapter XI-2 after the attacks of September 2001, provides a framework for ships and ports to detect and deter security threats.

Security levels: Level 1 (normal; minimum protective measures at all times), Level 2 (heightened; additional measures for a period of increased risk), Level 3 (exceptional; specific measures when an incident is probable or imminent). The flag state sets the ship's level; the port state sets the port's level.
People: the Ship Security Officer (SSO) on board, the Company Security Officer (CSO) ashore, and the Port Facility Security Officer (PFSO).
Documents: the approved Ship Security Plan (SSP), which is confidential; the International Ship Security Certificate (ISSC); and a Declaration of Security (DoS) where needed between ship and port or another ship.
Ship Security Alert System (SSAS): a covert alert that sends a message to the company and flag state without alerting anyone near the ship.
Records of the last 10 port calls and their security levels are kept.

For the OOW, ISPS means controlling access at the gangway (identification, search of persons and baggage as the level requires), watching restricted areas, keeping a lookout for suspicious craft, and knowing the anti-piracy measures in the SSP and industry guidance (Best Management Practices) for high-risk areas.

Port State Control

Port state control (PSC) is the inspection of foreign ships in national ports to verify that their condition, equipment and crew comply with the conventions. Regional agreements coordinate PSC: the Paris MoU covers Europe and the North Atlantic (including the UK), the Tokyo MoU the Asia-Pacific, and the US Coast Guard runs its own programme.

How an inspection works

Initial inspection: the inspector checks the certificates and documents and makes a general check of the ship's condition and crew.
More detailed inspection: if there are "clear grounds" to believe the ship or crew do not comply (for example, missing certificates, obvious defects, a crew unable to carry out basic drills, or a report from a pilot).
Expanded inspection: for ships with a high risk profile, under the Paris MoU's risk-based regime.
Detention: if deficiencies are clearly hazardous to safety, health or the environment, the ship is detained until they are rectified. Detentions are published and harm the ship's and company's reputation and future inspection rate.

Preparing as OOW

Know where the certificates, record books, logbooks and plans are kept.
Keep the Oil Record Book, Garbage Record Book, logbook and hours of rest records accurate and up to date.
Make sure the navigational equipment works, charts and publications are corrected, and the passage plan is complete berth to berth.
Be ready to demonstrate the operation of equipment (GMDSS, BNWAS, ECDIS alarms, emergency steering) and to take part in a drill.
Answer the inspector honestly; do not guess. Saying "I would check the SMS procedure, which is here" is far better than bluffing.

Common deficiencies include fire doors and dampers, ISM failures, life-saving appliances, ECDIS (including lack of type-specific training), hours of rest, pilot ladders and oily water separators.

The MCA Oral Examination

Where it fits

To gain a UK OOW (Unlimited) Certificate of Competency under STCW Regulation II/1, you must complete the approved training and sea service set out in MSN 1856, pass the required written examinations or approved academic route, and then pass the MCA oral examination. Candidates who started training from August 2025 follow the modernised syllabus in MIN 720; check which route applies to you.

Booking and format

MIN 690 explains how the oral is booked and conducted. In outline:

When your sea service, training and certificates are complete, you apply to the MCA for assessment and receive a Notice of Eligibility (NoE), which lists anything still outstanding and is valid for a set period.
You then book your examination. For OOW (Unlimited), the MCA currently runs it in two parts: a computer-based, proctored Part A and an oral Part B with an MCA examiner. MIN 690 has been amended several times (including the delivery method and the rules on waiting periods after an unsuccessful attempt), so read the latest version before you book.
The syllabus for the oral is set out in MIN 653 and the MCA deck syllabuses. Check the current amendment.

The oral itself is a one-to-one conversation with an examiner (a master mariner), typically lasting about an hour. You will be asked to explain what you would do in practical situations, identify lights and shapes, describe procedures and apply the conventions. The result is normally given at the end, with feedback on any areas that need more work.

What the examiner is looking for

The examiner is asking one question throughout: "Would I be happy with this person keeping a watch on a ship, alone on the bridge at 0300?" That means:

Safe, practical decisions, with the reason for each.
Sound knowledge of the COLREGs, with the rule behind each action.
Knowing when to call the master, and not being afraid to do so.
Honesty about the limits of your knowledge.
Clear, calm communication, as you would use on the bridge.

Typical topics and questions

Area	Typical questions
COLREGs	Identify lights or shapes; what is this vessel doing and what do you do? Explain Rules 2, 5, 6, 7, 8, 10, 13 to 19. You are in restricted visibility and detect a target on radar ahead; what do you do?
Watchkeeping	How do you take over the watch? When do you call the master? Duties under MGN 315 at anchor and with a pilot on board.
Navigation and passage planning	The four stages of passage planning; parallel indexing; under-keel clearance and squat; ECDIS safety settings.
Radar and ARPA	Errors and limitations; trial manoeuvre; true and relative vectors.
Shiphandling	Turning circle terms; squat; interaction; anchoring procedure; pilot ladder rules.
Emergencies	Man overboard; fire on deck at sea; collision; grounding; abandon ship; GMDSS distress procedure.
SAR and GMDSS	Sea areas; DSC; SART; NAVTEX; search patterns.
Regulations	SOLAS Chapter V; ISM and the DPA; MARPOL discharge rules and record books; MLC hours of rest; ISPS security levels; port state control.
Stability and cargo	GM, free surface effect, load lines, basic cargo care for your ship type.

How to answer

A good structure for any scenario question is:

Assess the situation: say what you see or understand ("This is a power-driven vessel over 50 m, underway, seen head on.").
State the rule or regulation: ("This is a head-on situation under Rule 14.").
Say what you would do, and when: ("I would alter course to starboard in ample time, making a large alteration readily apparent to the other vessel, and sound one short blast.").
Say how you would check it: ("I would monitor the bearing and range, and the CPA on ARPA, until she is past and clear.").
Know when to involve others: ("If in doubt, I would call the master, while taking action myself.").

Other tips:

Listen to the whole question, and ask the examiner to repeat it if needed. Do not answer the question you expected.
Do not bluff. If you do not know, say so and say where you would find the answer on board (the SMS, the master's standing orders, the relevant MSN or publication). Confident wrong answers on safety matters are the most common reason for failure.
Think about safety first. In nearly every scenario, safe speed, a proper lookout, the master and the engine room are part of the answer.

Worked Example: Answering an Oral Scenario

Examiner: "You are OOW at night in the English Channel, in the south-west lane of the Dover Strait TSS. Visibility is good. You see a white masthead light, a second masthead light higher and abaft it, and a red sidelight, bearing about 30° on your starboard bow. What is it, and what do you do?"

A strong answer: "That is a power-driven vessel of 50 metres or more in length, underway, showing me her port side, so she is crossing from starboard to port ahead of me. I would take a compass bearing and check the ARPA target for CPA and TCPA. If the bearing is steady and the range closing, risk of collision exists."

Examiner: "The bearing is steady. She is crossing the traffic lane."

Continued answer: "She should cross the lane on a heading as nearly as practicable at right angles to the traffic flow, but Rule 10 does not relieve either of us of our obligations under the other rules. She is on my starboard side, so under Rule 15 I am the give-way vessel. Under Rules 8 and 16 I would take early and substantial action, probably an alteration to starboard to pass astern of her, first checking that it is safe with respect to other traffic in the lane. I would sound one short blast as I altered. If traffic was heavy or I had any doubt, I would call the master and consider reducing speed. Then I would keep checking the bearing until she was past and clear."

The examiner wants exactly this chain: identify, apply the rule, act safely with a reason, check, and involve the master when appropriate. Note how the candidate used the new information to apply the rules, rather than guessing in advance.

Common Mistakes

Quoting rules without explaining actions. The examiner wants to know what you would do, not just which rule number applies.
Bluffing. It is better to say "I don't know, but I would find it in the SMS or ask the master" than to invent a figure.
Forgetting the master. Many scenarios end with "and I would call the master". Know when MGN 315 and the standing orders say you must.
Confusing the discharge rules. Mix up 15 ppm with 30 litres per mile, or 3 nm with 12 nm, and the examiner will probe your whole MARPOL knowledge.
Arriving tired or underprepared. Use a structured revision plan and practise speaking answers aloud with a colleague.

Final Checklist Before the Oral

Your NoE is valid and the exam is booked through the current MIN 690 process; you have your ID and documents ready, and your equipment works for any online part.
You can identify every combination of lights and shapes from COLREG Part C and Annex I quickly, and state the vessel's status and your action.
You can explain each steering and sailing rule (Rules 4 to 19) and apply them to scenarios, including restricted visibility and TSS.
You can describe a full watch handover, the circumstances for calling the master, and the duties at anchor and with a pilot (MGN 315).
You can describe the four stages of passage planning (appraisal, planning, execution, monitoring) and explain UKC, squat and ECDIS safety settings.
You can explain radar errors, ARPA limitations and a trial manoeuvre.
You can describe man overboard turns, fire, flooding, collision, grounding and abandon ship actions, and the GMDSS distress procedure.
You can explain SAR roles and search patterns.
You can summarise SOLAS Chapter V, the ISM Code, MARPOL Annexes I to VI and BWM, MLC hours of rest, ISPS and PSC as they affect the OOW.
You have practised answering aloud using the structure: assess, rule, action, check, master.

Summary

IMO conventions are applied by flag states and checked by port states. The four pillars are SOLAS, MARPOL, STCW and MLC.
SOLAS Chapter V is the OOW's chapter: equipment, steering, charts, danger messages, assistance to persons in distress and voyage planning.
The ISM Code requires an SMS with policy, procedures, reporting, emergency preparedness and audits; a DPA links ship and shore; the master has overriding authority. The company holds a DOC; the ship an SMC.
MARPOL: 15 ppm for machinery space oily water; tanker cargo residues more than 50 nm, 30 litres per mile; ORB kept three years. Annex V prohibits plastics everywhere and limits food waste to 3 or 12 nm; Garbage Record Book kept two years. Annex VI: 0.50% sulphur globally, 0.10% in ECAs.
BWM: D-1 exchange at 200 nm and 200 m depth (or 50 nm), D-2 treatment for all ships from September 2024.
MLC and STCW: at least 10 hours' rest in any 24 and 77 in any 7 days, in no more than two periods, one at least six hours.
ISPS: three security levels; SSO, CSO and PFSO; the SSP is confidential; SSAS gives a covert alert.
PSC can detain a ship for serious deficiencies; know your records and equipment.
The MCA oral tests whether you are safe to keep a watch. Answer with the situation, the rule, the action and its reason, the check, and when you would call the master.

Check Your Understanding

What is the role of the Designated Person Ashore under the ISM Code?

Answer: To provide a link between the company and those on board, with direct access to the highest level of management, and to monitor the safety and pollution prevention aspects of each ship's operation, making sure adequate resources and shore support are provided.

Under what conditions may a ship of 400 GT discharge oily water from her machinery spaces outside a special area?

Answer: While proceeding en route, through approved oil filtering equipment, with an oil content without dilution not exceeding 15 ppm, with the alarm and automatic stopping device working, and provided the mixture does not come from cargo pump rooms of oil tankers or contain cargo residues. Then the operation is entered in the Oil Record Book Part I.

What are the rules for discharging comminuted food waste outside and inside special areas?

Answer: Outside special areas, comminuted food waste (25 mm or less) may be discharged not less than 3 nm from the nearest land while en route. Inside special areas, only comminuted food waste and not less than 12 nm from land, en route. Plastics may never be discharged.

State the minimum hours of rest under MLC and STCW.

Answer: At least 10 hours in any 24-hour period and 77 hours in any 7-day period. Rest may be split into no more than two periods, one at least six hours long, and the interval between consecutive periods must not exceed 14 hours.

What is the sulphur limit for fuel in an Emission Control Area, and what must be recorded during changeover?

Answer: 0.10% by mass. The date, time and position of the start and completion of the changeover, and the volume of low-sulphur fuel in each tank, must be recorded as required by Annex VI and the flag state.

Describe the D-1 ballast water exchange standard.

Answer: Exchange at least 200 nm from the nearest land in water at least 200 m deep, or if that is not possible, at least 50 nm from land in water at least 200 m deep, achieving at least 95% volumetric exchange (three times the tank volume pumped through for the flow-through method). The D-2 performance standard, using an approved treatment system, now applies to all ships.

What are the three ISPS security levels?

Answer: Level 1, normal, with minimum protective measures at all times; Level 2, heightened, with additional measures during a period of increased risk; Level 3, exceptional, with specific measures when a security incident is probable or imminent.

What gives a port state control inspector "clear grounds" for a more detailed inspection? Give three examples.

Answer: Any three of: missing or invalid certificates; evidence of serious defects in the hull, equipment or LSA; crew unable to communicate or carry out essential drills or operations; false or missing entries in record books; a report or complaint from a pilot, port authority or crew member; evidence of pollution.

In the oral, the examiner asks a question you do not know the answer to. What should you do?

Answer: Say honestly that you do not know, and explain where on board you would find the answer (the SMS, standing orders, the relevant MSN, MGN or publication) or who you would ask, such as the master. Never bluff, especially on safety matters.