I:\ASSEMBLY\20\RES\868

INTERNATIONAL MARITIME ORGANIZATION

IMO

E

A 20/Res.868

1 December 1997

Original: ENGLISH

ASSEMBLY

20th session

Agenda item 11

RESOLUTION A.868(20)

 adopted on 27 November 1997

GUIDELINES FOR THE CONTROL AND MANAGEMENT OF SHIPS' BALLAST 

WATER TO MINIMIZE THE TRANSFER OF HARMFUL 

AQUATIC ORGANISMS AND PATHOGENS

THE ASSEMBLY,

RECALLING Article 15(j) of the Convention on the International Maritime Organization concerning 

the functions of the Assembly in relation to regulations and guidelines concerning prevention and control of 

marine pollution from ships,

RECALLING ALSO resolution A.774(18) by which it recognized that the uncontrolled discharge of 

ballast water and sediment from ships has led to the transfer of harmful aquatic organisms and pathogens, 

causing injury to public health and damage to property and the environment, and accordingly adopted 

Guidelines for Preventing the Introduction of Unwanted Aquatic Organisms and Pathogens from Ships' Ballast 

Water and Sediment Discharges, and further that the Marine Environment Protection Committee (MEPC) and 

the Maritime Safety Committee (MSC) shall keep the ballast water issue and the application of the Guidelines 

under review with a view to further developing the Guidelines as a basis for a new Annex to MARPOL 73/78,

RECALLING FURTHER that the 1992 United Nations Conference on Environment and

Development (UNCED), in its Agenda 21 requests IMO to consider the adoption of appropriate rules on 

ballast water discharge to prevent the spread of non-indigenous organisms, and further proclaims in its 

Declaration on Environment and Development that States shall widely apply the precautionary approach 

according to their capabilities,

BEARING IN MIND that MEPC/Circ.288 recognized that the existing Guidelines do not provide a 

complete solution towards the total prevention of the introduction of harmful aquatic organisms and pathogens, 

but urged that focus should be directed on measures aimed at minimizing the risks, emphasizing further that in 

applying the existing Guidelines, the ship's safety was of paramount importance,

NOTING the objectives of the Convention on Biological Diversity, 1992, and that the transfer and 

introduction of alien aquatic species with ballast water threatens the conservation and sustainable use of 

biological diversity,
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NOTING FURTHER the status of work carried out by MEPC as requested by resolution A.774(18) 

concerning the development of legally binding provisions on ballast water management together with guidelines 

for their effective implementation, as well as the Guidance on Safety Aspects of Ballast Water Exchange at 

Sea prepared by the Sub-Committee on Ship Design and Equipment, and distributed as MEPC/Circ.329 and 

MSC/Circ.806, both of 30 June 1997,

RECOGNIZING that several States have taken unilateral action by adopting legally binding provisions 

for local, regional or national application with a view to minimizing the risks of introducing harmful aquatic 

organisms and pathogens through ships entering their ports, and also that this issue, being of worldwide 

concern, demands action based on globally applicable regulation together with guidelines for their effective 

implementation and uniform interpretation,

HAVING CONSIDERED the recommendation of the MEPC at its fortieth session on this issue,

1. ADOPTS the Guidelines for the Control and Management of Ships' Ballast Water to Minimize the 

Transfer of Harmful Aquatic Organisms and Pathogens set out in the Annex to the present resolution;

2. REQUESTS Governments to take urgent action in applying these Guidelines, including the

dissemination thereof to the shipping industry, to use them as a basis for any measures they adopt with a view 

to minimizing the risks of introducing harmful aquatic organisms and pathogens, and to report to the MEPC on 

any experience gained in their implementation;

3. REQUESTS ALSO the MEPC to work towards completion of legally binding provisions on ballast 

water management in the form of a new Annex to MARPOL 73/78, together with guidelines for their uniform 

and effective implementation with a view to their consideration and adoption in the year 2000;

4. REQUESTS FURTHER the MSC to include in its workplan the evaluation of information received 

from interested parties, particularly that relevant to 12.2 of the Guidelines adopted herewith, with a view to 

determining the hazards and potential consequences for various existing ship types and operations. The MSC 

is also requested to consider any other relevant issues concerning ballast water management as well as design 

objectives for new ships, with a view to minimizing to the extent possible risks of introducing harmful aquatic 

organisms and pathogens with ships' ballast water and sediments;

5. REVOKES resolution A.774(18).
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ANNEX

GUIDELINES FOR THE CONTROL AND MANAGEMENT OF SHIPS' BALLAST WATER 

TO MINIMIZE THE TRANSFER OF HARMFUL AQUATIC ORGANISMS AND 

PATHOGENS

Contents

CHAPTER 1 - INTRODUCTION

CHAPTER 2 - DEFINITIONS

CHAPTER 3 - APPLICATION

CHAPTER 4 - GUIDELINE OBJECTIVES AND BACKGROUND

CHAPTER 5 - DISSEMINATION OF INFORMATION

CHAPTER 6 - TRAINING AND EDUCATION

CHAPTER 7 - PROCEDURES FOR SHIPS AND PORT STATES

7.1 Procedures for ships

7.2 Procedures for port States

CHAPTER 8 - RECORDING AND REPORTING PROCEDURES

8.1 Procedures for ships

8.2 Procedures for port States

CHAPTER 9 - SHIPS' OPERATIONAL PROCEDURES

9.1 Precautionary practices

.1 Minimizing uptake of harmful aquatic organisms, pathogens and sediments

.2 Removing ballast sediment on a timely basis

.3 Avoiding unnecessary discharge of ballast water

9.2 Ballast water management options

.1 Ballast water exchange

.2 Non-release or minimal release of ballast water

.3 Discharge to reception facilities

.4 Emergent and new technologies and treatments

CHAPTER 10 - PORT STATE CONSIDERATION
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10.1 Highly disparate conditions between uptake and discharge ports

10.2 Ballast water age

10.3 Presence of target organisms

CHAPTER 11 - ENFORCEMENT AND MONITORING BY PORT STATES

CHAPTER 12 - FUTURE CONSIDERATIONS IN RELATION TO BALLAST WATER

EXCHANGE

12.1 Research needs

12.2 Long-term evaluation of safety aspects in relation to ballast water exchange

CHAPTER 13 - BALLAST SYSTEM DESIGN

Appendix 1 - Ballast water reporting form

Appendix 2 - Guidance on safety aspects of ballast water exchange at sea
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1 Introduction

1.1 Studies carried out in several countries have shown that many species of bacteria, plants, and animals 

can survive in a viable form in the ballast water and sediment carried in ships, even after journeys of several 

months' duration. Subsequent discharge of ballast water or sediment into the waters of port States may result 

in the establishment of harmful aquatic organisms and pathogens which may pose threats to indigenous human, 

animal and plant life, and the marine environment. Although other media have been identified as being 

responsible for transferring organisms between geographically separated water bodies, ballast water discharge 

from ships appears to have been among the most prominent.

1.2 The potential for ballast water discharge to cause harm has been recognised not only by the 

International Maritime Organization but also by the World Health Organization, which is concerned about the 

role of ballast water as a medium for the spreading of epidemic disease bacteria.

1.3 These Guidelines are not to be regarded as a certain solution to the problem. Rather, each part of 

them should be viewed as a tool which, if correctly applied, will help to minimize the risks associated with 

ballast water discharge. As scientific and technological advances are made, the Guidelines will be refined to 

enable the risk to be more adequately addressed. In the interim, port States, flag States and other parties that 

can assist in mitigating this problem should exercise due care and diligence in an effort to conform to the 

maximum extent possible with the Guidelines.

1.4 The selection of appropriate methods of risk minimization will depend upon several factors, including 

the type or types of organisms being targeted, the level of risk involved, its environmental acceptability, the 

economic and ecological costs involved and the safety of ships.

2 Definitions

For the purposes of these Guidelines, the following definitions apply:

Administration means the Government of the State under whose authority the ship is operating.

Convention means MARPOL 73/78 (International Convention for the Prevention of Pollution from 

Ships, 1973, and the Protocol of 1978 related thereto).

Member States means States that are Members of the International Maritime Organization.

Organization means the International Maritime Organization (IMO).

Port State authority means any official or organisation authorized by the Government of a port State 

to administer guidelines or enforce standards and regulations relevant to the implementation of national 

and international shipping control measures.

Treatment means a process or mechanical, physical, chemical or biological method to kill, remove or 

render infertile, harmful or potentially harmful organisms within ballast water.

3 Application

The Guidelines are directed to Member States and can apply to all ships; however, a port State 

authority shall determine the extent to which they do apply.

4 Guideline objectives and background
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4.1 The objectives of these Guidelines, developed under technical and scientific guidance, are intended to 

assist Governments and appropriate authorities, ship masters, operators and owners, and port authorities, as 

well as other interested parties, in minimizing the risk of introducing harmful aquatic organisms and pathogens 

from ships' ballast water and associated sediments while protecting ships' safety.

4.2 The Guidelines allow port States to exempt ships within the area under their jurisdiction from part or 

all of the relevant provisions. Notwithstanding, any administration wishing to apply restrictions to ballast water 

operations should still follow these Guidelines, when developing legislation or procedures.

4.3 In order that the Guidelines may be implemented in a standard and uniform manner, all Member State 

Governments, ship operators, other appropriate authorities and interested parties are requested to apply these 

Guidelines.

5 Dissemination of information

5.1 Administrations are encouraged to maintain and exchange information relevant to these Guidelines 

through the Organization. Accordingly, administrations are encouraged to provide the Organization with the 

following:

.1 Information on severe outbreaks or infestations of harmful aquatic organisms which may pose 

a risk;

.2 Copies of current domestic laws and regulations;

.3 Technical and research information;

.4 Education materials (such as audio and video tapes) and printed materials; and

.5 Location and terms of use of alternative exchange zones, contingency strategies, availability 

of shore reception facilities, fees, etc.

5.2 Member States, applying ballast water and sediment discharge procedures, should notify the 

Organization of specific requirements and provide to the Organization, for the information of other Member 

States and non-governmental organizations, copies of any regulations, standards, exemptions or guidelines being 

applied. Verification and detailed information concerning port State requirements should be obtained by the 

ship prior to arrival.

5.3 Port State authorities should provide the widest possible distribution of information on ballast water and 

sediment management and treatment requirements that are being applied to shipping. Failure to do so may lead 

to unnecessary delays for ships seeking entry to port States.

5.4 Shipping organizations and ships' managers should be familiar with the requirements of port State 

authorities with respect to ballast water and sediment management and treatment procedures, including 

information that will be needed to obtain entry clearance.

5.5 Member States are invited to provide the Organization with details of any research and development 

studies that they carry out with respect to the impact and control of harmful aquatic organisms and pathogens 

in ships' ballast water and sediment.
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5.6 Member States should provide to the Organization details of records describing reasons why existing 

requirements could not be complied with, e.g. force majeure, heavy weather, failure of equipment, or lack of 

information concerning port State requirements.

6 Training and education 

6.1 Training for ships' masters and crews as appropriate should include instructions on the application of 

ballast water and sediment management and treatment procedures, based upon the information contained in 

these Guidelines. Instruction should also be provided on the maintenance of appropriate records and logs. 

Governments should ensure that their marine training organizations include this in the contents of their syllabus.

6.2 The application of processes and procedures concerning ballast water management are currently at 

the core of the solution to minimize the introduction of harmful aquatic organisms and pathogens.

6.3 Governments are encouraged to include knowledge of duties regarding the control of pollution of the 

sea by harmful aquatic organisms and pathogens in their training requirements for certificates.

7 Procedures for ships and port States

7.1 Procedures for ships

7.1.1 Every ship that carries ballast water should be provided with a ballast water management plan to assist 

in the minimization of transfer of harmful aquatic organisms and pathogens. The intent of the plan should be to 

provide safe and effective procedures for ballast water management.

7.1.2 The ballast water management plan should be specific to each ship.

7.1.3 The ballast water management plan should be included in the ship's operational documentation. Such a 

plan should address, inter alia:

- relevant parts of these Guidelines;

- approval documentation relevant to treatment equipment;

- an indication of records required; and

- the location of possible sampling points.

7.2 Procedures for port States

7.2.1 Reception and treatment facilities should be made available for the environmentally safe disposal of 

ballast tank sediments.

7.2.2 Discharge of ship's ballast water into port reception and/or treatment facilities may provide an 

acceptable means of control. Port State authorities wishing to utilize this strategy should ensure that the 

facilities are adequate.
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8 Recording and reporting procedures

8.1 Procedures for ships

8.1.1 Where a port State authority requires that specific ballast water procedures and/or treatment option(s) 

be undertaken, and due to weather, sea conditions or operational impracticability such action cannot be taken, 

the master should report this fact to the port State authority as soon as possible and, where appropriate, prior to 

entering seas under its jurisdiction.

8.1.2 To facilitate the administration of ballast water management and treatment procedures on board each 

ship, a responsible officer should be appointed to maintain appropriate records and to ensure that ballast water 

management and/or treatment procedures are followed and recorded.

8.1.3 When taking on or discharging ballast water, as a minimum, the dates, geographical locations, ship's 

tank(s) and cargo holds, ballast water temperature and salinity as well as the amount of ballast water loaded or 

discharged should be recorded. A suitable format is shown in appendix 1. The record should be made 

available to the port State authority.

8.1.4 The location and suitable access points for sampling ballast or sediment should be described in the 

ship's ballast water management plan. This will allow crew members to provide maximum assistance when 

officers of the port State authority require a sample of the ballast water or sediment.

8.2 Procedures for port States

8.2.1 Consistent with 5.2 above, port States should provide ships with the following information:

- details of their requirements concerning ballast water management;

- location and terms of use of alternative exchange zones;

- any other port contingency arrangements; and

- the availability, location, capacities of and applicable fees relevant to reception facilities that 

are being provided for the environmentally safe disposal of ballast water and associated 

sediment.

8.2.2 To assist ships in applying the precautionary practices described in 9.1.1 below, port States should 

inform local agents and/or the ship of areas and situations where the uptake of ballast water should be 

minimized, such as:

- areas with outbreaks, infestations or known populations of harmful organisms and pathogens;

- areas with current phytoplankton blooms (algal blooms, such as red tides);

- nearby sewage outfalls;

- nearby dredging operations;

- when a tidal stream is known to be the more turbid; and

- areas where tidal flushing is known to be poor.
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9 Ships' operational procedures

9.1 Precautionary practices

9.1.1 Minimizing uptake of harmful aquatic organisms, pathogens and sediments

When loading ballast, every effort should be made to avoid the uptake of potentially harmful aquatic 

organisms, pathogens and sediment that may contain such organisms. The uptake of ballast water should be 

minimized or, where practicable, avoided in areas and situations such as:

- areas identified by the port State in connection with advice relating to 8.2.2 above;

- in darkness when bottom-dwelling organisms may rise up in the water column;

- in very shallow water; or

- where propellers may stir up sediment.

9.1.2 Removing ballast sediment on a timely basis

Where practicable, routine cleaning of the ballast tank to remove sediments should be carried out in 

mid-ocean or under controlled arrangements in port or dry dock, in accordance with the provisions of the ship's 

ballast water management plan.

9.1.3 Avoiding unnecessary discharge of ballast water

If it is necessary to take on and discharge ballast water in the same port to facilitate safe cargo 

operations, care should be taken to avoid unnecessary discharge of ballast water that has been taken up in 

another port.

9.2 Ballast water management options

9.2.1 Ballast water exchange

Near-coastal (including port and estuarine) organisms released in mid-ocean, and oceanic organisms 

released in coastal waters, do not generally survive.

When exchanging ballast at sea, guidance on safety aspects of ballast water exchange as set out in 

appendix 2 should be taken into account. Furthermore, the following practices are recommended:

- where practicable, ships should conduct ballast exchange in deep water, in open ocean and as 

far as possible from shore. Where this is not possible, requirements developed within regional 

agreements may be in operation, particularly in areas within 200 nautical miles from shore. 

Consistent with 9.1.2 above, all of the ballast water should be discharged until suction is lost, 

and stripping pumps or eductors should be used if possible;

- where the flow-through method is employed in open ocean by pumping ballast water into the 

tank or hold and allowing the water to overflow, at least three times the tank volume should be 

pumped through the tank;
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- where neither form of open ocean exchange is practicable, ballast exchange may be accepted 

by the port State in designated areas; and

- other ballast exchange options approved by the port State.

9.2.2 Non-release or minimal release of ballast water

In cases where ballast exchange or other treatment options are not possible, ballast water may be 

retained in tanks or holds. Should this not be possible, the ship should only discharge the minimum essential 

amount of ballast water in accordance with port States' contingency strategies.

9.2.3 Discharge to reception facilities

If reception facilities for ballast water and/or sediments are provided by a port State, they should, 

where appropriate, be utilized.

9.2.4 Emergent and new technologies and treatments

9.2.4.1 If suitable new and emergent treatments and technologies prove viable, these may substitute for, or be 

used in conjunction with, current options. Such treatments could include thermal methods, filtration, disinfection 

including ultraviolet light, and other such means acceptable to the port State.

9.2.4.2 Results concerning the application and effectiveness of new ballast water management technologies 

and associated control equipment should be notified to the Organization with a view to evaluation and 

incorporation, as appropriate, into these Guidelines.

10 Port State considerations

The following is provided for the guidance of port State authorities in the implementation of their ballast 

water management programme, and to assess risks in relation to the ballast water containing harmful aquatic 

organisms and pathogens.

10.1 Highly disparate conditions between uptake and discharge ports

Significantly different conditions may exist between port(s) of origin and the port in which ballast water 

is discharged. Examples include freshwater ballast being released into highly saline ports. There may be 

organisms capable of surviving such extreme transfers; however, there is a lower probability of species 

establishment under such transport events.

10.2 Ballast water age

The length of time during which ballast water is within an enclosed ballast tank may also be a factor in 

determining the number of surviving organisms, because of the absence of light, decreasing nutrients and 

oxygen, changes of salinity and other factors. However, the maximum length of survival of organisms in 

ballast water varies, and in many cases is not known. Water of an age of 100 days should be considered the 

minimum for applying this consideration. Ballast water and sediments may contain dinoflagellate cysts and 

other organisms capable of surviving for a much longer length of time.
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10.3 Presence of target organisms

10.3.1 Under certain circumstances it may be possible to determine if one or more target species are present 

in the water of a specific port and have been ballasted in a ship. In these circumstances, the receiving port 

State authority may invoke management measures accordingly. Even if such target species are not present, 

however, it should be noted that the ship may still be carrying many untargetted species which, if released in 

new waters, could be potentially harmful.

10.3.2 Port States are encouraged to carry out biological baseline surveys in their ports and to disseminate the 

results of their investigations.

11 Enforcement and monitoring by port states

11.1 Consistent with the precautionary approach to environmental protection, these Guidelines can apply to 

all ships unless specifically exempted by a port State authority within its jurisdiction. In accordance with 5.2 

above, port State authorities should inform the Organization on how the Guidelines are being applied.

11.2 Member States have the right to manage ballast water by national legislation. However, any ballast 

discharge restrictions should be notified to the Organization.

11.3 In all cases, a port State authority should consider the overall effect of ballast water and sediment 

discharge procedures on the safety of ships and those on board. Guidelines will be ineffective if compliance is 

dependent upon the acceptance of operational measures that put a ship or its crew at risk. Port States should 

not require any action of the master which imperils the lives of seafarers or the safety of the ship.

11.4 It is essential that ballast water and sediment management procedures be effective as well as 

environmentally safe, practicable, designed to minimize costs and delays to the ship, and based upon these 

Guidelines whenever possible.

11.5 Any instructions or requirements of a ship should be provided in a timely manner and be clear and

concise.

11.6 Port States should on request provide a visiting ship with any requested information relative to ballast 

water management and its potential effects with respect to harmful aquatic organisms and pathogens.

11.7 Any enforcement or monitoring activities should be undertaken in a fair, uniform and nationally 

consistent manner at all ports within the port State. Where there are compelling reasons whereby nationally 

consistent procedures cannot be followed, then deviations should be reported to the Organization.

11.8 Compliance monitoring should be undertaken by port State authorities by, for example, taking and 

analysing ballast water and sediment samples to test for the continued survival of harmful aquatic organisms 

and pathogens.

11.9 Where ballast water or sediment sampling for compliance or effectiveness monitoring is being 

undertaken, port State authorities should minimize delays to ships when taking such samples.

11.10 When sampling for research or compliance monitoring, the port State authority should give as much 

notice as possible to the ship that sampling will occur, to assist in planning staffing and operational resources.

11.11 The master has a general obligation to provide reasonable assistance for the above monitoring which 

may include provision of officers or crew, provision of the ship's plans, records pertaining to ballast 

arrangements and details concerning the location of sampling points.
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11.12 Sampling methods for research and monitoring is the responsibility of the individual port State. The 

Organization welcomes information on new or innovative methods of sampling and/or analysis, and any 

relevant information should be provided to it.

11.13 Port State authorities should indicate to the master or responsible officer the purpose for which a 

sample is taken (i.e., monitoring, research or enforcement). Results of analyses of samples should be made 

available to ship's operators on request.

11.14 Port State authorities may sample or require samples to analyse ballast water and sediment, before 

permitting a ship to proceed to discharge its ballast water in environmentally sensitive locations. In the event 

that harmful aquatic organisms or pathogens are found to be present in the samples, a port State's contingency 

strategy may be applied.
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12 Future considerations in relation to ballast water exchange

12.1 Research needs

Operational measures such as ballast water exchange may be appropriate in the short term; however, 

there is a clear need for further research. These Guidelines should be revised and adjusted in the light of 

results concerning new ballast water management options.

12.2 Long-term evaluation of safety aspects in relation to ballast water exchange

Recognizing the need to evaluate the hazards and potential consequences for various types of ships 

and operations, interested parties should carry out detailed studies and provide information relevant to:

- experience gained from carrying out ballast water exchange at sea, including any

samples/model procedures;

- operational precautions and procedures implemented to avoid potential hazards and

consequences that may arise during the ballast water exchange at sea;

- an evaluation of the safety margins between the actual metacentric height and stresses versus 

the allowable seagoing limits specified in the approved trim and stability booklet and loading 

manual, relevant to different types of ships and loading conditions;

- any hazards which may arise due to human element issues relative to the responsible 

execution of ballast water exchange at sea in a manner which may not be fully prudent;

- operational procedures carried out prior to initiating the ballast water exchange at sea and 

check points during the exchange;

- the extent of training and management necessary to ensure that the process of ballast water 

exchange at sea is effectively monitored and controlled on board;

- plan of action to incorporate any unique procedures should an emergency occur which may 

affect the exchange of ballast water at sea; and

- the decision-making process, taking into account relevant safety matters, including ship's 

position, weather conditions, machinery performance, ballast system inspection and

maintenance, crew safety and availability.

13 Ballast system design

Builders, owners and classification societies should take these Guidelines into consideration when 

designing new ships or modifying existing ships.
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APPENDIX 1
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APPENDIX 2

GUIDANCE ON SAFETY ASPECTS OF BALLAST WATER EXCHANGE AT SEA

1 Introduction

1.1 This document is intended to provide guidance on the safety aspects of ballast water exchange at sea. 

 The different types of ships which may be required to undertake ballast water exchange at sea make it 

presently impractical to provide specific guidelines for each ship type. Shipowners are cautioned that they 

should consider the many variables that apply to their ships. Some of these variables include type and size of 

ship, ballast tank configurations and associated pumping systems, trading routes and associated weather 

conditions, port State requirements and manning.

1.2 Ballast water exchange at sea procedures contained in relevant management plans should 

be individually assessed for their effectiveness from the environmental protection point of view as 

well as from the point of view of their acceptability in terms of structural strength and stability.

1.3 In the absence of a more scientifically based means of control, exchange of ballast water in deep 

ocean areas or open seas currently offers a means of limiting the probability that fresh water or coastal aquatic 

species will be transferred in ballast water. Two methods of carrying out ballast water exchange at sea have 

been identified:

.1 the sequential method, in which ballast tanks are pumped out and refilled with clean water; 

and/or

.2 the flow-through method, in which ballast tanks are simultaneously filled and discharged by 

pumping in clean water.

2 Safety precautions

2.1 Ships engaged in ballast water exchange at sea should be provided with procedures which account for 

the following, as applicable:

.1 avoidance of over and under-pressurization of ballast tanks;

.2 free surface effects on stability and sloshing loads in tanks that may be slack at any one time;

.3 admissible weather conditions;

.4 weather routeing in areas seasonably affected by cyclones, typhoons, hurricanes, or heavy 

icing conditions;

.5 maintenance of adequate intact stability in accordance with an approved trim and 

stability booklet;

.6 permissible seagoing strength limits of shear forces and bending moments in accordance with 

an approved loading manual;

.7 torsional forces, where relevant;

.8 minimum/maximum forward and aft draughts;
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.9 wave-induced hull vibration;

.10 documented records of ballasting and/or de-ballasting;

.11 contingency procedures for situations which may affect the ballast water exchange at sea, 

including deteriorating weather conditions, pump failure, loss of power, etc.;

.12 time to complete the ballast water exchange or an appropriate sequence thereof, taking into 

account that the ballast water may represent 50 % of the total cargo capacity for some ships; 

and

.13 monitoring and controlling the amount of ballast water.

2.2 If the flow through method is used, caution should be exercised, since:

.1 air pipes are not designed for continuous ballast water overflow;

.2 current research indicates that pumping of at least three full volumes of the tank capacity 

could be needed to be effective when filling clean water from the bottom and overflowing 

from the top; and

.3 certain watertight and weathertight closures (e.g. manholes) which may be opened during 

ballast exchange, should be re-secured.

2.3 Ballast water exchange at sea should be avoided in freezing weather conditions. However, when it is 

deemed absolutely necessary, particular attention should be paid to the hazards associated with the freezing of 

overboard discharge arrangements, air pipes, ballast system valves together with their means of control, and 

the accretion of ice on deck. 

2.4 Some ships may need the fitting of a loading instrument to perform calculations of shear forces and 

bending moments induced by ballast water exchange at sea and to compare with the permissible strength 

limits.

2.5 An evaluation should be made of the safety margins for stability and strength contained in allowable 

seagoing conditions specified in the approved trim and stability booklet and the loading manual, relevant to 

individual types of ships and loading conditions. In this regard particular account should be taken of the 

following requirements:

.1 stability to be maintained at all times to values not less than those recommended by the 

Organization (or required by the Administration);

.2 longitudinal stress values not to exceed those permitted by the ship's classification society with 

regard to prevailing sea conditions; and

.3 exchange of ballast in tanks or holds where significant structural loads may be generated by 

sloshing action in the partially filled tank or hold to be carried out in favourable sea and swell 

conditions so that the risk of structural damage is minimized.

2.6 The ballast water management plan should include a list of circumstances in which ballast water 

exchange should not be undertaken. These circumstances may result from critical situations of an exceptional 
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nature, force majeure due to stress of weather, or any other circumstances in which human life or safety of 

the ship is threatened.

3 Crew training and familiarization

3.1 The ballast water management plan should include the nomination of key shipboard control personnel 

undertaking ballast water exchange at sea.

3.2 Ships' officers and ratings engaged in ballast water exchange at sea should be trained in and 

familiarized with the following:

.1 the ship's pumping plan, which should show ballast pumping arrangements, with positions of 

associated air and sounding pipes, positions of all compartment and tank suctions and pipelines 

connecting them to ship's ballast pumps and, in the case of use of the flow through method of 

ballast water exchange, the openings used for release of water from the top of the tank 

together with overboard discharge arrangements;

.2 the method of ensuring that sounding pipes are clear, and that air pipes and their non-return 

devices are in good order;

.3 the different times required to undertake the various ballast water exchange operations;

.4 the methods in use for ballast water exchange at sea if applicable with particular reference to 

required safety precautions; and 

.5 the method of on-board ballast water record keeping, reporting and recording of routine 

soundings.

________