S3 - Updating and Correcting Nautical Charts.pptx

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1. Updating and correcting NAUTICAL CHARTS

2. Correcting and updating a navigation chart is a constant process. Once a chart is published, constantly changing navigational features and aids or other relevant information have to be promulgated in order to update the ships navigating in those areas.

3. Old, non updated Nautical Charts  should never be used for maritime navigation and voyage planning. The characteristics of a river, in particular, portrayed on a marine chart tends to change continuously, and artificial navigational aids at sea or shores may be altered at any time. As a result, never use obsolete or incorrect nautical charts for navigation and passage planning. Every manufacturer of nautical charts also includes a system for notifying seafarers of changes to the chart, corrections and updates needed to be applied to the chart.

4. A nautical chart is a graphic representation of a sea area and adjacent coastal regions. Depending on the scale of the chart, it may show  depths of water  and  heights of land  (topographic map), natural features of the  seabed , details of the  coastline , navigational  hazards , locations of  natural and human-made aids  to navigation, information on  tides  currents, local details of the Earth’s  magnetic field , and human-made structures such as  harbors ,  buildings , and  bridges . Nautical Charts are essential tools for marine navigation; many countries require vessels, especially commercial ships, to carry them. 

5. Nautical charting may take the form of charts printed on paper or computerized electronic navigational charts. Recent technologies have made available  paper charts  which are  printed “on demand”  with cartographic data that has been downloaded to the commercial printing company as recently as the night before printing. With each daily download, critical data such as  Local Notices to Mariners  are added to the on-demand chart files so that these marine charts are up to date at the time of printing . Worth to remember: as stated in the Mariners Handbook, “No chart is infallible. Every nautical chart is liable to be incomplete”.

6. The navigational chart in use by the officers on the vessels’ bridge for the passage planning must continually be updated to always reflect the most recent  Notices to Mariners corrections . In the event of a marine accident, failure to do so will be considered negligence and the captains, managers, and vessel owners may all be held accountable for damages.

7. Changes in depth, missing navigational lights, and new wrecks and obstructions are just a few of the challenges that are continuously changing on the waterways. A lot of these alterations aren’t visible to the human eye. Commercial ship mariners and recreational boaters both rely on nautical charts.

8. “Recreational boaters, unlike commercial mariners, are not required to carry nautical charts. But as more demands are put on our waterways, busy coasts mean more risk for accidents,” says Capt. John Lowell, director of NOAA’s Office of Coast Survey who added: “By using charts that are current, people have a better chance of avoiding potential groundings and other sea accidents”.

9. Because conditions at sea and beneath the water are constantly changing, we must have the most up-to-date data to ensure our safety at sea. Is there a recent wreck, and if so, where is it so we can stay away from it? Is there a buoy that has been damaged by a storm, and if so, do we know about it so that we can avoid crashing with it at night? Are shallower depths reported in a specific region, and if so, how do we know? Because information is always changing, a foolproof, controlled, and  certified system of chart correction  is required. Beside the charts, this corrections and updates system encompasses all hydrographic survey publications as well .

10. Corrections to Charts and Nautical Publications - why its important? Why do marine charts need to be updated?  Nautical Charts are ‘living’ documents. Information affecting the safety of navigation for mariners is constantly being received. Sometimes it is in the form of an individual report of a newly discovered danger, or a buoy or beacon has been moved or removed, while other times the change can be as large as an entire new survey. In all cases, the various national Hydrographic Offices have an obligation to publish details of new and altered information affecting the potential safety of mariners. Equally, many mariners have a legal obligation to apply these updates to their nautical charts – having your maritime navigation charts up-to-date is much more than a good idea actually for all vessels, ranging from large cargo ships to racing yachts.

11. Whenever a new area is to be added to a chart or it has to represent an area different from the previous chart, or the depth units shown on previous charts have to be changed or if the scale on which a previous chart was made has to be renewed, then Admiralty publishes a New Chart.

12. However if there are major changes in a chart or large amount of data is to be inserted  for e.g. Insertion of a New Traffic Separation Scheme not present on the previously used chart, the Admiralty then publishes a New Edition of that chart replacing the existing one.

13. The Catalogue of Admiralty Charts and Publications is published every year with current and updated editions of charts, however, if during the year the Weekly Notices to Mariner indicate any new editions or new charts, they are to be inserted in the chart catalogue by the navigating officer.

14. An updated and corrected chart folio system comprises of  Chart correction Log and Folio Index, Admiralty Chart catalogue, Admiralty Sailing Directions , Weekly Notices to Mariners , Annual Summary of Notices to Mariners,   Admiralty List of Lights , Admiralty List of Radio Signals , Admiralty Tide tables , Chart – 5011 Symbols and abbreviations to be used  on charts.  The following points to be considered in order to maintain updated chart folio onboard:

15. . The chart correction log should have details of all charts present onboard with index of corrections (temporary and preliminary also) mentioned against each chart number. All the charts and publications are to be corrected on weekly basis following instructions provided in weekly notices to mariners and the correction numbers to be entered in the same index mentioned above against chart numbers respectively, so that it can be used as a quick reference to check status of corrections for any chart

16. . There should be a designated chart supplier or service provided on a timely basis without delays to supply new charts and new editions applicable to the folios onboard. Other than that weekly Notice to mariners, Annual summary of Notices to Mariners, their supplements should be provided There should be equipment onboard and services to receive Navigational warnings, and  Navtex   warning

17. . Whenever a new chart or new edition is published, Weekly Notices to Mariner carry a notification of the same. On receiving a new edition or a new chart the chart correction log is to be updated with the relevant folio number against the chart number in the index and ‘NC’ or ‘NE’ to be inserted adjacent to the chart number in the correction index. The chart to be verified for any pending temporary and preliminary corrections and navigational warnings

18. . On receiving a chart or a notification through weekly notices to mariners which replaces a previous chart , insert in the chart correction log ‘replaced by’ or ‘cancelled by’ against the mentioned chart. The folio number to be inserted on the replacement chart received. The Admiralty Chart Catalogue ( NP 131),Weekly Notices to Mariners , Cumulative Notices to Mariners and Annual summary of Admiralty Notices to mariners are important sources of keeping a Chart folio system updated and corrected. For guidance on correcting charts Admiralty has published – How to Correct Charts the Admiralty Way which describes various forms of corrections applied to charts and upkeep of folios. The importance of keeping charts updated can be understood from the below incident.

19. Correcting and upgrading a navigation chart is a constant process. Once a chart is published, constantly changing navigational features and aids or other relevant information have to be promulgated in order to update the ships navigating in those areas.

20. Admiralty Notices to Mariners or Weekly Notices serve the purpose of correcting and updating charts, which are being supplied to the vessels electronically or in paper format . Weekly Notices to Mariners Issued on a weekly basis by the Admiralty, these notices contain corrections to charts and various other publications such as Admiralty sailing directions and Admiralty list of lights and radio signals. They also include temporary and preliminary notices to correct charts. The year begins with notice no .1 being issued in first week of January and the numbering increases chronologically till last week of the year. They also notify about any new charts or new editions being published and their previous editions being cancelled.

21. The corrections are mentioned either in the form of co ordinates with instructions or in the form of overlay chart tracings and blocks to be cut and pasted. New editions of Admiralty list of lights and fog signals, Admiralty Sailing directions and Admiralty List of Radio Stations are provided when available.

22. Cumulative List of Notices to mariners These are published twice a year in January and July. The main purpose of them is to provide a list of current editions of all Admiralty Charts and the serial numbers of notices affecting them which have been issued in previous two years. The charts present onboard can be verified for any missing corrections by checking them against the Cumulative Lists.

23. Annual Summary of Notices to Mariners All the temporary and preliminary notices for a previous year are being published collectively in Annual Summary of Notices to Mariners. They are quick and handy references available to determine which all temporary and permanent corrections are applicable to a chart. They also contain summary of corrections to sailing directions.

24. Chart correction software and computer ( Chart Co) The paper copy of weekly notices to mariners is digitized using software popularly named as Chart Co. Being online with a chart correction service provider, this organizes chart folios onboard in the form of a database and the corrections received being individually listed under respective charts. A navigating officer can then access the system using chart number to print and apply any specific or all applicable corrections for any chart present onboard. There is an offline database and software in use onboard ships where corrections are supplied in the form of weekly mail attachments. These are used to keep the chart correction database up to date exactly like the paper copy of Weekly Notices to Mariners.

25. Navarea Warnings : Navarea warnings are promulgated to ships operating in various areas. The world is divided into 21 NAV AREAS and these warnings are broadcasted by World Wide Navigational Warning Service. Through a network of Area Coordinators and National coordinators important international, coastal and local warnings and notices related to navigation are transmitted to ships which they receive using MF/HF radio frequencies and satellite networks.

26. Navtex Warnings:  These are broadcasted by Telex Broadcasting stations established in various coastal areas. Mostly they broadcast navigational, meteorological and distress warnings. They play a vital source of providing early warning in coastal navigation. A receiver onboard named as a Navtex Receiver is used to receive Navigational warnings. E.g. In  Dec. 2004 the Navtex stations were the first to broadcast urgency and distress warnings related to Tsunami to fishing and other merchant vessels operating in Indian ocean and adjacent coastal areas.

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