GUIDELINES FOR INVESTIGATIONS AND INSPECTIONS
CARRIED OUT UNDER MARPOL ANNEX I
PART 1
INSPECTION OF IOPP CERTIFICATE, SHIP AND EQUIPMENT
1 Ships required to carry an IOPP Certificate
1.1 On boarding and introduction to the master or responsible ship’s officer, the port State
control officer (PSCO) should examine the International Oil Pollution Prevention Certificate
(IOPP Certificate), including the attached Supplement – Record of Construction and Equipment
for ships other than oil tankers or Record of Construction and Equipment for oil tankers, and
the Oil Record Book (ORB). The ORB may be presented in an electronic format. A declaration
from the Administration should be viewed in order to accept this electronic record book. If a
declaration cannot be provided, a hard copy record book will need to be presented for
examination.
1.2 The certificate carries the information on the type of ship and the dates of surveys
and inspections. As a preliminary check it should be confirmed that the dates of surveys and
inspections are still valid. Furthermore, it should be established if the ship carries an oil cargo
and whether the carriage of such oil cargo is in conformity with the certificate (see also
paragraph 1.11 of the Record of Construction and Equipment for Oil Tankers).
1.3 Through examining the Record of Construction and Equipment, the PSCO may
establish how the ship is equipped for the prevention of marine pollution.
1.4 If the certificate is valid and the general impression and visual observations on board
confirm a good standard of maintenance, the PSCO should generally confine the inspection to
reported deficiencies, if any.
1.5 If, however, the PSCO from general impressions or observations on board has clear
grounds for believing that the condition of the ship or its equipment does not correspond
substantially with the particulars of the certificate, a more detailed inspection should be
initiated.
1.6 The inspection of the engine-room should begin with forming a general impression of
the state of the engine-room, the presence of traces of oil in the engine-room bilges and the
ship’s routine for disposing of oil-contaminated water from the engine-room spaces.
1.7 Next, a closer examination of the ship’s equipment as listed in the IOPP Certificate
may take place. This examination should also confirm that no unapproved modifications have
been made to the ship and its equipment.
1.8 Should any doubt arise as to the maintenance or the condition of the ship or its
equipment, then further examination and testing may be conducted as considered necessary.
In this respect reference is made to annex 3 to the Survey Guidelines under the Harmonized
System of Survey and Certification (HSSC), 2023 (resolution A.1186(33)), as may be
amended.
1.9 The PSCO should bear in mind that a ship may be equipped over and above the
requirements of MARPOL Annex I. If such equipment is malfunctioning, the flag State should
be informed. This alone, however, should not cause a ship to be detained unless the
discrepancy presents an unreasonable threat of harm to the marine environment.
1.10 In the case of oil tankers, the inspection should include the cargo tank and pump-room
area of the ship and should begin with forming a general impression of the layout of the tanks,
the cargoes carried, and the routine of cargo slops disposal.
2 Ships of non-Parties to MARPOL Annex I and other ships not required to carry an IOPP Certificate
2.1 As this category of ships is not provided with an IOPP Certificate, the PSCO should
be satisfied with regard to the construction and equipment standards relevant to the ship on
the basis of the requirements set out in MARPOL Annex I.
2.2 In all other respects the PSCO should be guided by the procedures for ships referred
to in section 1 above.
2.3 If the ship has some form of certification other than the IOPP Certificate, the PSCO
may take the form and content of this documentation into account in the evaluation of that ship.
3 Control
In exercising the control functions, the PSCO should use professional judgement to determine
whether to detain the ship until any noted deficiencies are corrected or to allow it to sail with
certain deficiencies which do not pose an unreasonable threat of harm to the marine
environment. In doing this, the PSCO should be guided by the principle that the requirements
contained in MARPOL Annex I, in respect of construction and equipment and the operation of
ships, are essential for the protection of the marine environment and that departure from these
requirements could constitute an unreasonable threat of harm to the marine environment.
PART 2
CONTRAVENTION OF DISCHARGE PROVISIONS
1 Experience has shown that information furnished to the flag State as envisaged in
appendix 5 of these Procedures is often inadequate to enable the flag State to cause
proceedings to be brought in respect of the alleged violation of the discharge requirements.
This appendix is intended to identify information which is often needed by a flag State for the
prosecution of such possible violations.
2 It is recommended that, in preparing a port State report on deficiencies, where
contravention of the discharge requirements is involved, the authorities of the coastal or port
State be guided by the itemized list of possible evidence as shown in part 3 of this appendix.It should be borne in mind in this connection that:
.1 the report aims to provide the optimal collation of obtainable data; however,
even if all the information cannot be provided, as much information as
possible should be submitted; and
.2 it is important for all the information included in the report to be supported by
facts which, when considered as a whole, would lead the port or coastal State
to believe a contravention had occurred.
3 In addition to the port State report on deficiencies, a report should be completed by a
port or coastal State on the basis of the itemized list of possible evidence. It is important that
these reports are supplemented by documents such as:
.1 a statement by the observer of the pollution; in addition to the information
required under section 1 of part 3 of this appendix, the statement should
include considerations which lead the observer to conclude that no other
possible pollution source is in fact the source;
.2 statements concerning the sampling procedures both of the slick and on
board; these should include location where and time when samples were
taken, identity of person(s) taking the samples and receipts identifying the
persons having custody and receiving transfer of the samples;
.3 reports of analyses of samples taken of the slick and on board; the reports
should include the results of the analyses, a description of the method
employed, reference to or copies of scientific documentation attesting to the
accuracy and validity of the method employed, and names of persons
performing the analyses and their experience;
.4 a statement by the PSCO on board together with the PSCO’s rank and
organization;
.5 statements by persons being questioned;
.6 statements by witnesses; all observations, photographs and documentation
should be supported by a signed verification of their authenticity;
all certifications, authentications or verifications shall be executed in
accordance with the laws of the State which prepares them; all statements
should be signed and dated by the person making the statement and, if
possible, by a witness to the signing; the names of the persons signing
statements should be printed in legible script above or below the signature;
.7 photographs of the oil slick; and
.8 copies or printouts of relevant recordings, etc., pages of ORBs, logbooks,
discharge.
4 The report referred to in paragraphs 2 and 3 should be sent to the flag State. If the
coastal State observing the pollution and the port State carrying out the investigation on board
are not the same, the State carrying out the latter investigation should also send a copy of its
findings to the State observing the pollution and requesting the investigation.
PART 3
ITEMIZED LIST OF POSSIBLE EVIDENCE ON ALLEGED CONTRAVENTION
OF THE MARPOL ANNEX I DISCHARGE PROVISIONS
1 Action on sighting oil pollution
1.1 Particulars of ship or ships suspected of contravention
.1 Name of ship
.2 Reasons for suspecting the ship
.3 Date and time (UTC) of observation or identification
.4 Position of ship
.5 Flag and port of registry
.6 Type (e.g. tanker, cargo ship, passenger ship, fishing vessel), size (estimated tonnage) and other descriptive data (e.g. superstructure colour
and funnel mark)
.7 Draught condition (loaded or in ballast)
.8 Approximate course and speed
.9 Position of slick in relation to ship (e.g. astern, port, starboard)
.10 Part of the ship from which side discharge was seen emanating
.11 Whether discharge ceased when ship was observed or contacted by radio
1.2 Particulars of slick
.1 Date and time (UTC) of observation if different from paragraph 1.1.3
.2 Position of oil slick in longitude and latitude if different from paragraph 1.1.4
.3 Approximate distance in nautical miles from the nearest land
.4 Approximate overall dimension of oil slick (length, width and percentage
thereof covered by oil)
.5 Physical description of oil slick (direction and form, e.g. continuous, in
patches or in windrows)
.6 Appearance of oil slick (indicate categories)
– Category A: Barely visible under most favourable light condition
– Category B: Visible as silvery sheen on water surface
– Category C: First trace of colour may be observed
– Category D: Bright band of colour
– Category E: Colours begin to turn dull
– Category F: Colours are much darker
.7 Sky conditions (bright sunshine, overcast, etc.), lightfall and visibility
(kilometres) at the time of observation
.8 Sea state
.9 Direction and speed of surface wind
.10 Direction and speed of current
1.3 Identification of the observer(s)
.1 Name of observer
.2 Organization with which observer is affiliated (if any)
.3 Observer’s status within the organization
.4 Observation made from aircraft/ship/shore/otherwise
.5 Name or identity of ship or aircraft from which observation was made
.6 Specific location of ship, aircraft, place on shore or otherwise from which
observation was made
.7 Activity engaged in by observer when observation was made, e.g. patrol,
voyage, flight (en route from … to …)
1.4 Method of observation and documentation
.1 Visual
.2 Conventional photographs
.3 Remote sensing records and/or remote sensing photographs
.4 Samples taken from slick
.5 Any other form of observation (specify)
Note: A photograph of the discharge should preferably be in colour. Photographs
can provide the following information: that a material on the sea surface is
oil; that the quantity of oil discharged does constitute a violation of the
Convention; that the oil is being, or has been, discharged from a particular
ship; and the identity of the ship.
Experience has shown that the aforementioned can be obtained with the
following three photographs:
– details of the slick taken almost vertically down from an altitude of less
than 300 m with the sun behind the photographer;
– an overall view of the ship and slick showing oil emanating from a
particular ship; and
– details of the ship for the purposes of identification.
1.5 Other information if radio contact can be established
.1 Master informed of pollution
.2 Explanation of master
.3 Ship’s last port of call
.4 Ship’s next port of call
.5 Name of ship’s master and owner
.6 Ship’s call sign
2 Investigation on board
2.1 Inspection of IOPP Certificate
.1 Name of ship
.2 Distinctive number or letters
.3 Port of registry
.4 Type of ship
.5 Date and place of issue
.6 Date and place of endorsement
Note: If the ship is not issued an IOPP Certificate, as much as possible of the
requested information should be given.
2.2 Inspection of Supplement of the IOPP Certificate
.1 Applicable paragraphs of sections 2, 3, 4, 5 and 6 of the Supplement (non-oil
tankers)
.2 Applicable paragraphs of sections 2, 3, 4, 5, 6, 7, 8, 9 and 10 of the
Supplement (oil tankers)
Note: If the ship does not have an IOPP Certificate, a description should be given
of the equipment and arrangements on board, designed to prevent marine
pollution.
2.3 Inspection of Oil Record Book (ORB)
.1 Copy or print out sufficient pages of the ORB – part I to cover a period of
30 days prior to the reported incident
.2 Copy or print out sufficient pages of the ORB – part II (if on board) to cover
a full loading/unloading/ballasting and tank cleaning cycle of the ship.
Also copy the tank diagram.
2.4 Inspection of logbook
.1 Last port, date of departure, draught forward and aft
.2 Current port, date of arrival, draught forward and aft
.3 Ship’s position at or near the time the incident was reported
.4 Spot check if positions mentioned in the logbook agree with positions noted
in the ORB
2.5 Inspection of other documentation on board
Other documentation relevant for evidence (if necessary, make copies) such as:
.1 recent ullage sheets
.2 records of monitoring and control equipment
2.6 Inspection of ship
.1 Ship’s equipment in accordance with the Supplement of the IOPP Certificate
.2 Samples taken. State location on board
.3 Traces of oil in vicinity of overboard discharge outlets
.4 Condition of engine-room and contents of bilges
.5 Condition of oily-water separator, filtering equipment and alarm, stopping or
monitoring arrangements
.6 Contents of sludge and/or holding tanks
.7 Sources of considerable leakage on oil tankers
The following additional evidence may be pertinent:
.8 Oil on surface of segregated or dedicated clean ballast
.9 Condition of pump-room bilges
.10 Condition of crude oil washing (COW) system
.11 Condition of inert gas (IG) system
.12 Condition of monitoring and control system
.13 Slop tank contents (estimate quantity of water and of oil)
2.7 Statements of persons concerned
If the ORB – part I has not been properly completed, information on the following questions
may be pertinent:
.1 Was there a discharge (accidental or intentional) at the time indicated on the
incident report?
.2 Is the bilge discharge controlled automatically?
.3 If so, at what time was this system last put into operation and at what time
was this system last put on manual mode?
.4 If not, what were the date and time of the last bilge discharge?
.5 What was the date of the last disposal of residue and how was disposal
effected?
.6 Is it usual to effect discharge of bilge water directly to the sea, or to store
bilge water first in a collecting tank? Identify the collecting tank.
.7 Have oil fuel tanks recently been used as ballast tanks?
If the ORB – part II has not been properly completed, information on the following questions
may be pertinent:
.8 What was the cargo/ballast distribution in the ship on departure from the last
port?
.9 What was the cargo/ballast distribution in the ship on arrival in the current
port?
.10 When and where was the last loading effected?
.11 When and where was the last unloading effected?
.12 When and where was the last discharge of dirty ballast?
.13 When and where was the last cleaning of cargo tanks?
.14 When and where was the last COW operation and which tanks were
washed?
.15 When and where was the last decanting of slop tanks?
.16 What is the ullage in the slop tanks and the corresponding height of
interface?
.17 Which tanks contained the dirty ballast during the ballast voyage (if ship
arrived in ballast)?
.18 Which tanks contained the clean ballast during the ballast voyage (if ship
arrived in ballast)?
In addition, the following information may be pertinent:
.19 Details of the present voyage of the ship (previous ports, next ports, trade)
.20 Contents of oil fuel and ballast tanks
.21 Previous and next bunkering, type of oil fuel
.22 Availability or non-availability of reception facilities for oily wastes during the
present voyage
.23 Internal transfer of oil fuel during the present voyage
In the case of oil tankers, the following additional information may be pertinent:
.24 The trade the ship is engaged in, such as short/long distance, crude or
product or alternating crude/product, lightering service, oil/dry bulk
.25 Which tanks are clean and dirty
.26 Repairs carried out or envisaged in cargo tanks
Miscellaneous information:
.27 Comments in respect of condition of ship’s equipment
.28 Comments in respect of pollution report
.29 Other comments
3 Investigation ashore
3.1 Analyses of oil samples
Indicate method and results of the samples’ analyses.
3.2 Further information
Additional information on the ship, obtained from oil terminal staff, tank cleaning
contractors or shore reception facilities may be pertinent.
Note: Any information under this heading is, if practicable, to be corroborated by
documentation such as signed statements, invoices, receipts.
4 Information not covered by the foregoing
5 Conclusion
.1 Summing up of the investigator’s technical conclusions.
.2 Indication of applicable provisions of MARPOL Annex I which the ship is
suspected of having contravened.
.3 Did the results of the investigation warrant the filing of a deficiency report?
PART 4
GUIDELINES FOR IN-PORT INSPECTION OF CRUDE OIL WASHING PROCEDURES
1 Preamble
1.1 Guidelines for the in-port inspection of crude oil washing (COW) procedures, as called
for by resolution 7 of the International Conference on Tanker Safety and Pollution Prevention,
1978, are required to provide a uniform and effective control of crude oil washing to ensure
compliance of ships at all times with the provisions of MARPOL.
1.2 The design of the crude oil washing installation is subject to the approval of the flag
Administration. However, although the operational aspect of crude oil washing is also subject
to the approval of the same Administration, it might be necessary for a port State authority to
see to it that continuing compliance with agreed procedures and parameters is ensured.
1.3 The COW Operations and Equipment Manual has been so specified that it contains
all the necessary information relating to the operation of crude oil washing on a particular
tanker. The objectives of the inspection would then be to ensure that the provisions of the
Manual dealing with safety procedures and with pollution prevention are being strictly adhered
to.
1.4 The method of the inspection is at the discretion of the port State authority and may
cover the entire operation or only those parts of the operation which occur when the PSCO is
on board.
1.5 Inspection will be governed by articles 5 and 6 of MARPOL.
2 Inspections
2.1 A port State should make the appropriate arrangements so as to ensure compliance
with requirements governing the crude oil washing of oil tankers. This is not, however, to be
construed as relieving terminal operators and shipowners of their obligations to ensure that
the operation is undertaken in accordance with the regulations.
2.2 The inspection may cover the entire operation of crude oil washing or only certain
aspects of it. It is thus in the interest of all concerned that the ship’s records with regard to the
COW operations are maintained at all times so that a PSCO may verify those operations
undertaken prior to the inspection.
3 Ship’s personnel
3.1 The person in charge and the other nominated persons who have responsibility in
respect of the crude oil washing operation should be identified. They must, if required, be able
to show that their qualifications meet the requirements, as appropriate, of paragraphs 5.2
and 5.3 of the Revised specifications for the design, operation and control of crude oil washing
systems (resolution A.446(XI)), as amended.
3.2 The verification may be accomplished by reference to the individual’s discharge
papers, testimonials issued by the ship’s operator or by certificates issued by a training centre
approved by an Administration. The numbers of such personnel should be at least as stated
in the Manual.
4 Documentation
The following documents should be available for inspection:
.1 the IOPP Certificate and the Record of Construction and Equipment, to
determine:
.1 whether the ship is fitted with a crude oil washing system as required
in regulation 33 of MARPOL Annex I;
.2 whether the crude oil washing system is according to and complying
with the requirements of regulations 33 and 35 of MARPOL Annex I;
.3 the validity and date of the Operations and Equipment Manual; and
.4 the validity of the Certificate;
.2 the approved Manual;
.3 the ORB; and
.4 the Cargo Ship Safety Equipment Certificate to confirm that the inert gas
system conforms to regulations contained in chapter II-2 of SOLAS 1974.
5 Inert gas system
5.1 Inert gas system regulations require that instrumentation be fitted for continuously
indicating and permanently recording at all times when inert gas is being supplied, the pressure
and the oxygen content of the gas in the inert gas supply main. Reference to the permanent
recorder would indicate if the system had been operating before and during the cargo
discharge in a satisfactory manner.
5.2 If conditions specified in the Manual are not being met, the washing must be stopped
until satisfactory conditions are restored.
5.3 As a further precautionary measure, the oxygen level in each tank to be washed is to
be determined at the tank. The meters used should be calibrated and inspected to ensure that
they are in good working order. Readings from tanks already washed in port prior to inspection
should be available for checking. Spot checks on readings may be instituted.
6 Electrostatic generation
It should be confirmed either from the cargo log or by questioning the person in charge that
the presence of water in the crude oil is being minimized as required by paragraph 6.7 of the
Revised specifications for the design, operation and control of crude oil washing systems
(resolution A.446(XI)), as amended.
7 Communication
It should be established that effective means of communication exist between the person in
charge and the other persons concerned with the COW operation.
8 Leakage on deck
PSCOs should ensure that the COW piping system has been operationally tested for leakage
before cargo discharge and that the test has been noted in the ship’s ORB.
9 Exclusion of oil from engine-room
It should be ascertained that the method of excluding cargo oil from the machinery space is
being maintained by inspecting the isolating arrangements of the tank washing heater (if fitted)
or of any part of the tank washing system which enters the machinery space.
10 Suitability of the crude oil
In judging the suitability of the oil for crude oil washing, the guidance and criteria contained in
section 9 of the COW Operations and Equipment Manual should be taken into account.
11 Checklist
It should be determined from the ship’s records that the pre-crude oil wash operational
checklist was carried out and all instruments functioned correctly. Spot checks on certain items
may be instituted.
12 Wash programmes
12.1 Where the tanker is engaged in a multiple port discharge, the ORB would indicate if
tanks were crude oil washed at previous discharge ports or at sea. It should be determined
that all tanks which will or may be used to contain ballast on the forthcoming voyage will be
crude oil washed before the ship departs from the port. There is no obligation to wash any tank
other than ballast tanks at a discharge port except that each of these other tanks must be
washed at least in accordance with paragraph 6.1 of the Revised specifications for the design,
operation and control of crude oil washing systems (resolution A.446(XI)), as amended.
The ORB should be inspected to check that this is being complied with.
12.2 All crude oil washing must be completed before a ship leaves its final port of
discharge.
12.3 If tanks are not being washed in one of the preferred orders given in the Manual, the
PSCO should determine that the reason for this and the proposed order of tank washing are
acceptable.
12.4 For each tank being washed it should be ensured that the operation is in accordance
with the Manual in that:
.1 the deck-mounted machines and the submerged machines are operating
either by reference to indicators, the sound patterns or other approved
methods;
.2 the deck-mounted machines, where applicable, are programmed as stated;
.3 the duration of the wash is as required; and
.4 the number of tank washing machines being used simultaneously does not
exceed that specified.
13 Stripping of tanks
13.1 The minimum trim conditions and the parameters of the stripping operations are to be
stated in the Manual.
13.2 All tanks which have been crude oil washed are to be stripped. The adequacy of the
stripping is to be checked by hand-dipping at least in the aftermost hand-dipping location in
each tank or by such other means provided and described in the Manual. It should be
ascertained that the adequacy of stripping has been checked or will be checked before the
ship leaves its final port of discharge.
14 Ballasting
14.1 Tanks that were crude oil washed at sea will be recorded in the ORB. These tanks
must be left empty between discharge ports for inspection at the next discharge port.
Where these tanks are the designated departure ballast tanks they may be required to be
ballasted at a very early stage of the discharge. This is for operational reasons and also
because they must be ballasted during cargo discharge if hydrocarbon emission is to be
contained on the ship. If these tanks are to be inspected when empty, this must be done shortly
after the tanker berths. If a PSCO arrives after the tanks have begun accepting ballast, the
sounding of the tank bottom would not be available. However, an examination of the surface
of the ballast water is then possible. The thickness of the oil film should not be greater than
that specified in paragraph 4.2.10(b) of the Revised specifications for the design, operation
and control of crude oil washing systems (resolution A.446(XI)), as amended.
14.2 The tanks that are designated ballast tanks will be listed in the Manual. It is, however,
left to the discretion of the master or responsible officer to decide which tanks may be used for
ballast on the forthcoming voyage. It should be determined from the ORB that all such tanks
have been washed before the tanker leaves its last discharge port. It should be noted that
where a tanker backloads a cargo of crude oil at an intermediate port into tanks designated for
ballast, then it should not be required to wash those tanks at that particular port but at a
subsequent port.
14.3 It should be determined from the ORB that additional ballast water has not been put
into tanks which have not been crude oil washed during previous voyages.
14.4 It should be verified that the departure ballast tanks are stripped as completely as
possible. Where departure ballast is filled through cargo lines and pumps these must be
stripped either into another cargo tank or ashore by the special small diameter line provided for this purpose.
14.5 The methods to avoid vapour emission where locally required will be provided in the
Manual and they must be adhered to. The PSCO should ensure that this is being complied
with.
14.6 The typical procedures for ballasting listed in the Manual must be observed.
The PSCO should ensure this is being complied with.
14.7 When departure ballast is to be shifted, the discharge into the sea must be in
compliance with regulations 15 and 34 of MARPOL Annex I. The ORB should be inspected to
ensure that the ship is complying with this.