What is the Polar Water Operational Manual?

South Georgia icebergs

And here we have another Polar Code related post, this time is a guide to the extra document that will have to be carried by ships operating in Polar Waters.

A key part of the Polar Code is the requirement to carry a Polar Water Operations Manual. This post gives a quick summary of the contents of that manual.

To comply with the Polar Code this manual must be carried onboard.

Click here for IMO MEPC 264 58>

What is the goal of the Polar Water Operational Manual?

To provide the owner, operator, master and crew with sufficient information regarding the ship’s operational capabilities and limitations in order to support their decision-making process when in Polar waters.

What are the Functional requirements of the PWOM?

The Manual should include or refer to:

  • Information on the ship-specific capabilities and limitations in relation to the assessment by the Polar Code
  •  Specific procedures to be followed in normal operations and in order to avoid encountering conditions that exceed the ship’s capabilities
  • Specific procedures to be followed in the event
    of incidents in polar waters
  • Specific procedures to be followed in the event that conditions are encountered which exceed the ship’s specific capabilities and limitations
  • Procedures to be followed when using icebreaker assistance, as applicable.

Note: The Manual also shall contain, where applicable, the methodology used to determine capabilities and limitations in ice.

What risk-based procedures should be included in the PWOM?Sun and Polar Seas

  • Voyage planning to avoid ice and/or temperatures that exceed the ship’s
    design capabilities or limitations
  • Arrangements for receiving forecasts of the environmental conditions;
  • Means of addressing any limitations of the hydrographic, meteorological
    and navigational information available
  • Operation of equipment required under other chapters of this Code
    Implementation of special measures to maintain equipment and system
    functionality under low temperatures, topside icing and the presence of sea
    ice, as applicable.
  • Contacting emergency response providers for salvage, search and rescue (SAR), spill response, etc., as applicable
  • In the case of ships ice strengthened in accordance with chapter 3,  procedures for maintaining life support and ship integrity in the event of prolonged entrapment by ice
  • Measures to be taken in the event of encountering ice and/or temperatures which exceed the ship’s design capabilities or limitations
  • Procedures for monitoring and maintaining safety during operations in ice, as applicable, including any requirements for escort operations or icebreaker assistance. Different operational limitations may apply depending on whether the ship is operating independently or with icebreaker escort. Where appropriate, the PWOM should specify both options.

What are the contents of the Polar Water Operational Manual (PWOM)?

Appendix 2 of the code contains a model table of a polar operations manual, here is a list Ice and mountain through a ship's windowof  PWOM contents derived from that Appendix.

Safety Measures

Division 1 – Operational capabilities and limitations

Chapter 1 Operation in ice
  • Operator guidance for safe operation
  • Icebreaking capabilities
  • Manoeuvring in ice
  • Special features Guidance
Chapter 2 Operation in low air temperatures
  • System design
Chapter 3 Communication and navigation capabilities in high latitudes
Chapter 4 Voyage duration

Division 2 – Ship operations

Chapter 1 Strategic planning
  • Avoidance of hazardous ice
  • Avoidance of hazardous temperatures
  • Voyage duration and endurance
  • Human resources management
Chapter 2 Arrangements for receiving forecasts of environmental conditionsElephant Seal and anchor
  • Ice information
  • Meteorological information
Chapter 3 Verification of hydrographic, meteorological and navigational information

Chapter 4 Operation of Special Equipment

  • Navigation systems
  • Communications systems
Chapter 5 Procedures to maintain equipment and system functionality
  • Icing prevention and de-icing
  • Operation of seawater systems
  • Procedures for low temperature operations

Division 3 – Risk management

Chapter 1 Risk mitigation in limiting environmental condition
  • Measures to be considered in adverse ice conditions
  • Measures to be considered in adverse temperature conditions
Chapter 2 Emergency response
  • Damage control
  • Firefighting
  • Escape and evacuation
Chapter 3 Coordination with emergency response services
  • Ship emergency response
  •  Salvage
Chapter 4 Procedures for maintaining life support and ship integrity in the event of
prolonged entrapment by ice.
  • System configuration
  • System operation

Division 4 – Joint operations

Chapter 1 Escorted operations
Chapter 2 Convoy operations

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What is the Polar Code Record of Equipment?

Glacier FootRecord of Equipment for the compliance with the international code for ships operating in polar waters- A quick guide

And so the Polar Code posts continue, and so it’s another excuse to dig out some of my favourite photos.
Like many of the other certificates the Polar Code Certificate must be supplemented by a record of equipment form, and like other certificates this is a useful form to have at hand when preparing for the arrival of the surveyor on-board.

This record shall be permanently attached to the Polar Ships Certificate

What is contained on the Polar Code record of Equipment?

Particulars of ship:

  • Name of ship
  • Distinctive number or letters

Record of equipmentKing Penguins at South Georgia

Life-saving appliances

  • Total number of immersion suits with insulation for crew and for passengers
  • Total number of thermal protective aids

Personal and Group Survival Equipment

  • Personal survival equipment – for number of persons
  • Group survival equipment – for number persons
  • Total capacity of liferafts in compliance with chapter 8 of the Polar Code
  • Total capacity of lifeboats in compliance with chapter 8 of the Polar Code

Navigation equipment

  • Two independent echo-sounding devices or a device with two separate independent transducers
  • Remotely rotatable, narrow-beam search lights controllable from the bridge or other means to visually detect ice
  • Manually initiated flashing red light visible from astern (for ships involved in icebreaking operations)
  • Two or more non-magnetic independent means to determine and display heading
  • GNSS compass or equivalent (for ships proceeding to latitudes over 80 degrees)

Communication equipment

  • Sound signaling system mounted to face astern to indicate escort and emergency Ice and mountainsmanoeuvres to following ships as described in the International Code of Signals (for ships intended to provide ice breaking escort).
  • Voice and/or data communications with relevant rescue coordination centres.
  • Equipment for voice communications with aircraft on 121.5 and 123.1 MHz.
  • Two-way voice and data communication with a Telemedical Assistance Service (TMAS).
  • All rescue boats and lifeboats have a device (for ships certified to operate in low air temperature):
    • For transmitting vessel to shore alerts
    • for transmitting signals for location
    • for transmitting and receiving on-scene communications
  • All other survival craft have a device:
    • for transmitting signals for location
    • for transmitting and receiving on-scene communications

A Really Handy Guide to Ship Certification-Part 4

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What is contained on the Polar Ship Certificate?


Navsregs>Ship Certification>

Certifying that a vessel is safe for Polar Waters

This new series of posts on the Polar Code continues with a look at the contents of the Polar Ship Certificate. A look that also gives me an excuse to enjoy using some of my favourite photographs. 

Which ships have to carry a valid Polar Ship Certificate?

Every ship to which the Code applies

Click here for information on which ships these are>

When is a Polar Ship Certificate issued?

After an initial or renewal survey.

For category C cargo ships however, if the result of and assessment is that no additional equipment or structural modification is required to comply with the Code, the Certificate may be issued based upon documented verification that the ship complies with all relevant requirements. An on board survey will be undertaken at the next scheduled survey.

Polar Ship Certificate validity, survey dates and endorsements shall be harmonized
with the relevant SOLAS certificates as  required by HSSC.

What should accompany the certificate?

A Record of Equipment for the Polar Ship Certificate.

What does the Polar Ship Certificate Certify?

  • That the ship has been surveyed in accordance with the applicable safety-relatedSea beginning to freeze
    provisions of the International Code for Ships Operating in Polar Waters.
  • That the survey showed that the structure, equipment, fittings, radio station arrangements, and materials of the ship and the condition thereof are in all respects satisfactory and that the ship complies with the relevant provisions of the Code

What is contained on the Polar Ship Certificate?

  • Particulars of ship
    • Name of ship
    • Distinctive number or letters
    • Port of registry
    • Gross tonnage
    • IMO number
  • Category A/B/C (see below)
  • Table of ice class against drafts fore and aft (maximum and minimum)
  • Ship type: tanker/passenger ship/other
  • Ship restricted to operate in ice free waters/open waters/other ice conditions
  • Ship intended to operate in low air temperature: Yes/No
  • Polar Service Temperature: ……..°C/not applicable
  • Maximum expected time of rescue


  • A statement that the ship was/was not subject to alternative design and arrangements.
  • A statement that a Document of approval of alternative design and arrangements for structure, machinery and electrical installations/fire protection/life-saving appliances and arrangements is/is not appended to this Certificate.
  • Operational limitations
    • Ice conditions
    • Temperature
    • High latitudesSmall iceberg

What is a polar code  Category A/B/C ship?

  • Category A ship means a ship designed for operation in polar waters in at least medium first-year ice, which may include old ice inclusions
  • Category B ship means a ship not included in category A, designed for operation in
    polar waters in at least thin first-year ice, which may include old ice inclusions
  • Category C ship means a ship designed to operate in open water or in ice conditions
    less severe than those included in categories A and B


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What is the Polar Code?

South Georgia skyline

I have been asked quite a few questions on the Polar Code recently, and the Navigation Lights series of posts have been put to one side for a while whilst I put together some facts about the new code.

The International Code for Ships Operating in Polar Waters, (The Polar Code), has been introduced by the IMO to safeguard both life and the environment. It therefore draws on both SOLAS and MARPOL for its authority. This post is a quick introduction to the code.

What is the purpose of the Polar Code?

The International Code for Ships Operating in Polar Waters has been developed to Anchor in the snowsupplement the SOLAS and MARPOL  Conventions in order to increase the safety of ships’ operation and mitigate the impact on the people and environment in the remote, vulnerable and potentially harsh polar waters.

How was the Polar Code introduced?

The polar code was introduced by the IMO resolution  MEPC.264(68)

It is mandated by Chapter XIV – of SOLAS ‘Safety Measures for Ships Operating in Polar Waters’ and by additional chapters to the Annexes of MARPOL

Which ships have to comply with the Polar Code?

To all ships operating in polar waters


Ships constructed before 1 January 2017 shall meet the relevant requirements of the Polar Code by the first intermediate or renewal survey, whichever occurs first, after the 1st of  January 2018.

It does not apply Ships owned or operated by a Contracting Government and used, for the time being, only in Government non-commercial service. However, ships owned or operated by a Contracting Government and used, for the time being, only in Government non-commercial service are encouraged to act in a manner consistent, so far as reasonable and practicable, with the code.

What are Polar Waters?

  • Antarctic: Further south than 60 South
  • Arctic:  Within a boundary defined in the code, this has a lowest latitude of 58 North off Greenland

Where can Information on the Polar Code be found?

Frozen sea and mountainsWhat does the Polar Code Cover?

This is best summarized by the chapter headings of its two sections.

Safety Measures

  • Chapter 1 -General
  • Chapter 2 – Polar Water Operation Manual (PWOM)
  • Chapter 3-Ship Structure
  • Chapter 4- Subdivision and Stability
  • Chapter 5- Watertight and Weathertight Integrity
  • Chapter 6-Machinery Installations
  • Chapter 7-Fire safety/Protection
  • Chapter 8-Life Saving Appliances and Arrangements
  • Chapter 9- Safety of Navigation
  • Chapter 10-Communication
  • Chapter 11- Voyage Planning
  • Chapter 12- Manning and Training

Pollution Prevention Measures

  • Chapter 1-Prevention of Pollution by Oil
  • Chapter 2-Control of Pollution by Noxious Liquid Substances in Bulk
  • Chapter 3-Prevention of Pollution by Harmful Substances Carried by Sea in Packaged Form
  • Chapter 4- Prevention of Pollution by Sewage from Ships
  • Chapter 5-Prevention of Pollution by Garbage from Ships

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Navigation Light Controller (NLC)-A quick guide the requirements


Bridge of general cargo ship

Some more information from Resolution MSC.253(83)

This post is a continuation from of the last post covering navigation lights performance standards.

Click here to view a cop of MSC 258>

What is a Navigation Light Controller?

Navigation Light Controller (NLC) is a device enabling operational control of a Navigation Light.

What are the requirements of a Navigation Light Controller?Bridge window with gold sun screens

  • An NLC should facilitate ON/OFF controls of individual NLs
  • An NLC should provide visual indications of ON/OFF status of NLs
  • An NLC on board a ship not less than 50 m in length should present the status of all NLs in a logical presentation, meeting the requirements set out in resolution MSC.191(79), e.g., by symbol marks on a display. Click here to view the resolution
  • All indicators of an NLC should be dimmable to ensure easy reading without disturbing the night vision of the Officer of the Watch. The brightness of a display, if fitted, of an NLC should be controllable.

Note: Pre-programmed NL group settings may be provided

What are the requirements regarding light failures?

An NLC on board a ship not less than 50 m in length should provide the alarm for:

  • A failure of power supply to the Navigation Lights
  • A failure, including short circuit, of a lamp which is switched ON.

An NLC should support the use of standardized serial interfaces for marine navigation and communication systems

The NLC should have a bi-directional interface to transfer alarms to external systems and receive acknowledgements of alarms from external systems. The interface should comply with the relevant international standards

Power supply and fallback arrangements

Each navigation light should be connected, via separate circuits, to a navigation light controller located on the bridge in order to avoid any navigation light failure, including short circuit, that affect any navigation lights connected to the controller.

Navigation lights and controllers, and associated equipment should be so constructed and installed, as necessary, that they are readily accessible for inspection and maintenance purposes.

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​Navigation Light Performance Standards-A handy guide to the IMO Resolution

Navsregs>COLREGS>Navigation light performance standards summary

Sunrise over a jettyResolution MSC.253(83) Performance Standards for Navigation lights, Navigation Light Controller and Associated Equipment

The last post contained a contents list of this Resolution, this post goes into a bit more detail with a summary of some of its contents.

Click here to view a cop of MSC 258>

What are the  navigation lights?

  • Masthead light
  • Sidelights
  • Sternlight
  • Towing light
  • All-round light
  • Flashing light
  • All-round flashing yellow light required for air-cushion vessels
  • Manoeuvering light

Note: Unless expressly required, these Navigation lights  should appear steady and non-flashing.

The document also refers to international standard  IEC 60945.

What material should navigation lights be produced in?Tug Masthead lights

Material that is:

  • Robust
  • Non-corroding material,
  • Should ensure a long-term durability for the optical qualities 

What is the requirement to carry spare Navigation lights and lamps?

  • A masthead light, sidelights and a sternlight installed on board a ship not less than 50m in length should be duplicated or be fitted with duplicate lamps
  • A sufficient number of spare lamps for Navigation lights should be carried onboard

: Only lamps specified by the manufacturer should be used.

By how much may the  Luminous intensity vary?

Within the prescribed sector in which the minimum luminous intensity is required the vertical intensity distribution of the light should be  uniform in such a way that the measured minimum and maximum luminous intensity values  do not differ by more than a factor of 1.5.

This is to avoid  intensity changes which may result in the appearance of a flashing light.

What special requirements are there for Navigation lights using LEDs?

  • An alarm  must notify the Officer of the Watch that the luminous intensity of the light reduces below the level required by COLREGs
  • The lifespan of LEDs should be determined and clearly notified by the manufacturer

What markings must a navigation light have?Navigation lights on a tug's mast

Each light should be marked with:

  • The type/category of the light
  • The serial and certificate number
  • Head line directions
  • Range in nautical miles
  • Nominal wattage of the light source in watts, if different values lead to different ranges. 

How should Navigation lights be installed?

Navigation lights should be installed in such a way so as:

  • To protect navigation watch keeping
  • To ensure that the light shows over the  required arcs of visibility
  • To satisfy the required vertical separation and location requirements in all normal operating trim conditions
  • So that the lamp specified by the manufacturer can be efficiently  and readily replaced, without elaborate re-calibration or readjustment
  • So that they are readily accessible for inspection and maintenance purposes

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Performance Standards for Navigation lights- A summary

Navsregs>COLREGS>Navigation light performance standards
LightandBlockAnd now,  the dive down into navigation light regulations now hits the bottom of detail with an IMO resolution. 

The post in Navigation light series gives a quick summary into the performance standards required of vessel’s navigation lights.

What document gives the performance Standards for Navigation lights?

​Resolution MSC.253(83)

Performance Standards for Navigation lights, Navigation Light Controller and Associated Equipment

Click here for the document>

Navigation Light equipment should be designed, tested, installed and maintained based on these standards.

What is the purpose of Navigation Lights?

  • Identify ships
  • Notify their intentions at sea 

What is the purpose of a Navigation Lights Controller?

is to provide means of:

  • Control of Navigation lights
  • Monitoring of the status of Navigation lights 

Stern light of a ferry

What is covered in MSC 253?

1 Scope

2 Application

3 Definitions

  • Associated equipmentLightCloseMast
  • Lamp
  • Length
  • Navigation Light (NL)
  • Navigation Light Controller (NLC)

4 Navigation Lights

  • General
  • Luminous intensity distribution
  • Special requirements for lights using LEDs

5 Navigation Light Controller

  • On off switches
  • Status indications
  • Pre-programming
  • Alarms
  • Dimming
  • Interfaces

6 Power supply and fallback arrangementsMast and flags of a bunker barhe

  • Need for separate circuits
  • Ability to operate  by an emergency source
  • Automatic switch over to the alternative source of power is permitted.

7 Associated equipment

  • General requirements for  associated equipment
  • Screens for sidelight may be a part of a ship’s structure.

8 Marking

The markings that each Navigation Light should have.

9 Installation of navigation lights and associated equipment.

The general requirements required of navigation lights

10 Maintenance

  • The requirements for the ease of replacing the lights
  • The requirements for the ability to maintain the lights

The next post will look at some of these performance standards in more detail.

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Where should a vessel’s sidelights be carried?

Sidelights have simpler rules on their placement than masthead lights, and therefore this post is shorter than the last.

Sidelights on MV Balmoral


  • ​ The sidelights of a power-driven vessel shall be placed at a height above the hull not greater than three quarters of that of the forward masthead light.
  •  They shall not be so low as to be interfered with by deck lights

The sidelights, if in a combined lantern and carried on a power-driven vessel of less than 20 meters in length, shall be placed not less than 1 meter below the masthead light.Port Sidelight


On a power-driven vessel of 20 meters or more in length:

  • The sidelights shall not be placed in front of the forward masthead lights.
  • They shall be placed at or near the side of the vessel

Sidelight position summary


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Where should a vessel’s masthead lights be placed?

Power Driven vessel end on

Navsregs>COLREGS>Masthead light position

More delving into the detail of navigation lights, this time its the positioning of masthead lights.

The vertical positioning of Masthead lights

What part of the COLREGs covers the vertical positioning of Masthead lights?

Annex 1 part 2.

At what height should masthead lights be carried?

On a power-driven vessel of 20 meters or more in length:

The forward masthead light, or if only one masthead light is carried, then that light is:

  • At a height above the hull of not less than 6 meters


  •  If the breadth of the vessel exceeds 6 meters, then at a height above the hull not less than such breadth, so however that the light need not be placed at a greater height above the hull than 12 meters

The masthead light of a power-driven vessel of 12 meters but less than 20 meters in length:

  •  Shall be placed at a height above the gunwale of not less than 2.5 meters.

The masthead light of a power-driven vessel of less than 12 meters in length:

  • These may carry the uppermost light at a height of less than 2.5 meters above the gunwale.
  • When however a masthead light is carried in addition to side-lights and a sternlight or the all-round light prescribed in Rule 23(c)(i) is carried in addition to sidelights, then such masthead light or all-round light shall be carried at least 1 meter higher than the

The masthead light or lights prescribed in shall be so placed as to be above and clear of all other lights and obstructions except for Not Under Command Lights and Restricted in Manoeuvrability.


What is the separation of two masthead lights?

The after one shall be at least 4.5 meters vertically higher than the forward one.

The vertical separation of masthead lights of power-driven vessels shall be such that in all normal conditions of trim the after light will be seen over and separate from the forward light at a distance of 1000 meters from the stem when viewed from sea level.

Horizontal positioning of Masthead lights

What part of the COREGS covers the horizontal positioning of Navigation lights?

Annex 1 3 Horizontal positioning and spacing of lights

the horizontal distance between them shall not be less than one half of the length of the vessel but need not be more than 100 meters. The forward light shall be placed not more than one quarter of the length of the vessel from the stem.

A quick summary of the Masthead Light distances


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The range of ship’s navigation lights

Navsregs>COLREGS>Navigation Light Range

​This post starts of with the simple facts of COLREG 22 and then delves deeper and deeper into definitions; deep into the world of lux, lumens and candelas.

Sunset in the Med

The range of Navigation lights

What Rule states the visibility of Navigation lights?

Rule 22-visibility of lights

Note: This Rule states that navigation lights shall have an intensity as specified in Section 8 of Annex I to the COLREGS.

What is the range of Navigation lights in a vessel of 50 meters or more in length?

  • Masthead light- 6 miles
  • Sidelight-3 miles
  • Sternlight-3 miles
  • Towing light-3 miles
  • A white, red, green or yellow all-round light-3 miles

What is the range of Navigation lights in a vessel of 12 meters or more in length but less than 50 meters in length?

  • Masthead light, 5 miles; except that where the length of the vessel is less than 20 meters, 3 miles
  • Sidelight- 2 miles
  • Sternlight-2 miles;
  • Towing light-2 miles;
  •  White, red, green or yellow all-round light-2 miles

What is the range of Navigation lights in a vessel of less than 12 meters in length?

  • Masthead light- 2 miles
  • Sidelight- 1 mile
  • A sternlight- 2 miles
  • Towing light-2 miles
  • White, red, green or yellow all-round light- 2 miles

What is the range of Navigation lights of an inconspicuous, partly submerged vessel or object being towed?

White all-round light- 3 miles.

Waiting for the amplitude

The intensity of Navigation lights

The intensity required to achieve the minimum range is derived from a formula given in Section 8 of Annex I to the Colregs.

The intensity formula

1=3.43 × 1 06×T × D2 × K-D

What do the parts of the Navigation light intensity formula mean?

I is luminous intensity in candelas under service conditions

The candela is the SI unit of luminous intensity.  It is the luminous power per unit solid angle emitted by a point light source in a particular direction.

Or to be more accurate, it  is the luminous intensity, in a given direction, of a source that emits monochromatic radiation of frequency 540×1012 hertz and that has a radiant intensity in that direction of 1/683 watt per steradian.

The steradian is a square radian, and is the SI unit of solid angle.

T is threshold factor 2 × 10-7 lux

The lux is the SI unit of illuminance and luminous emittance, measuring luminous flux per unit area.It is equal to one lumen per square metre. It is used as a measure of the intensity, as perceived by the human eye.

The lumen is  the SI unit of luminous flux, a measure of the total quantity of visible light emitted by a source.

D is range of visibility (luminous range) of the light in nautical miles

The luminous range is the maximum distance at which a light can be seen, as determined by the luminous intensity of the light, the atmospheric transmission factor and the threshold of illuminance on the eye of the observer.

Ship's at anchor off Gibraltar

 K is atmospheric transmissivity.

Atmospheric transmissivity is he ratio of the directly transmitted flux incident on a surface after passing through unit thickness of the atmosphere to the flux that would be incident on the same surface if the flux had passed through a vacuum.

The value of K shall be 0.8, corresponding to a meteorological visibility of approximately 13 nautical miles.

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