Tag Archives: Navigation equipment

The Safety of Navigation and the Polar Code

Iceberg through a bridge window

A handy summary of the safety of Navigation elements of the polar code.

Another part of the Polar Code looked at in this blog, and another chance to share some ice photos.

Navigation in the polar regions present some challenges, and the Polar code contains some important requirements to meet those challenges.

What part of the Polar Code covers the safety of Navigation?

Chapter 9

What are the requirements for Navigational equipment functionality?

The navigational equipment and systems shall be:

  • Designed
  • Constructed
  • Installed

-to retain their functionality under the expected environmental conditions in the area of operation.

Systems for providing reference headings and position fixing shall be suitable for the intended areas.

What additional navigational equipment is required under the Polar Code?

Detecting the ice

  • Ships shall have means of receiving and displaying current information on ice

    Sea ice forming at South Georgia

    conditions in the area of operation

  • Ships shall have the ability to visually detect ice when operating in darkness
  • Two remotely rotatable, narrow-beam search lights controllable from the bridge to provide lighting over an arc of 360 degrees, or other means to visually detect ice. This is not required by vessels  solely operating in areas with 24 hours daylight


  • Either two independent echo-sounding devices or one echo-sounding device with two separate independent transducers. This applies to ships constructed on or after 1 January 2017 that are  ice strengthened in accordance with chapter 3 of the code
  • Two non-magnetic means to determine and display their heading.Both means shall be independent and shall be connected to the ship’s main and emergency source of power
  • Ships proceeding to latitudes over 80 degrees shall be fitted with at least one GNSS compass or equivalent, which shall be connected to the ship’s main and emergency source of power
  • For ships operating in areas, and during periods, where ice accretion is likely to occur, means to prevent the accumulation of ice on antennas required for navigation and communication
  • For ice strengthened ships  where equipment required by SOLAS chapter V or the Polar Code  have sensors that project below the hull, such sensors shall be protected against ice.

Rock formation at Hystviken

Working with icebreakers

  • Ships involved in operations with an icebreaker escort shall be equipped with a manually initiated flashing red light visible from astern to indicate when the ship is stopped.

This light shall have a range of visibility of at least two nautical miles, and the horizontal and vertical arcs of visibility shall conform to the stern light specifications in the COLREGS.

What are the Polar Code requirements regarding bridge design?

Ships shall comply with SOLAS regulation V/, irrespective of the date of construction and the size and, depending on the bridge configuration, a clear view astern.

In category A and B ships constructed on or after 1 January 2017, the bridge wings shall be enclosed or designed to protect navigational equipment and operating personnel.

dscf3338The Really Handy Revisions Aids for Kindle

Navsbooks publishes a range of revision aids for mariners studying for professional examinations. Each one has been written for the Kindle format, each one is at a handy price. They cover Colregs, Certification, Seamanship, ISM, and IALA.

Click here to learn more>

Tagged , ,

​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

Click to view this Handy Revision Guide for Kindle on Amazon

A Really Handy Guide to learn the Collision Regulations

This is the first in the series of Kindle revision guides covering the COLREGS.

Click here to view on Amazon>

Tagged , ,

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.

The Really Handy Books

HandyBooksThis is a series of COLREG revision books formatted for Kindle Readers.

Click for more information about the range>

Tagged ,

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


Follow Navsregs and Navsbooks





Tagged ,