About ENCs

ENC-image

NZ ENC are official vector Charts published by the New Zealand Hydrographic Authority (NZHA) providing coverage of New Zealand territory waters. The NZHA distributes its national ENCs for free under the NZ ENC Service.

They can be used in IMO compatible Electronic Chart Display and Information System (ECDIS) or in a compatible Electronic Chart System (ECS) which can decrypt IHO S-63 data.

NZ ENCs are essential for:

  • Vessels navigating in New Zealand on an IMO compliant ECDIS, to meet SOLAS Chapter V regulations covering the carriage of electronic charts and ECDIS. For further details visit the Maritime New Zealand website
  • Commercial vessels 12 metres or more in length and engaged in New Zealand domestic operations, to meet the National Standards for Commercial Vessels (NSCV) when used in IMO compliant ECDIS. For further details visit the Maritime New Zealand website

For a comprehensive overview about electronic charts (ENC and RNC), electronic charting systems (ECDIS and ECS) and electronic chart carriage requirements under the International Convention on the Safety of Life at Sea (SOLAS), we recommend you read the following IHO publication:

Facts about Electronic Charts and Carriage Requirements

This publication is written in an easy to read “question and answer” style and answers over twenty of the most commonly asked questions about electronic charts and their use in ECDIS and ECS. It contains the following information:

Section 1 An overview of electronic charting and regulations. This section explains what an ECDIS is, what an ECS is, what constitutes an ENC, what an RNC is, what ‘RCDS’ mode on an ECDIS is and explains chart carriage requirements under SOLAS regulations.
Section 2 A list of contacts for detailed information on Flag State Implementation of ECDIS.
Section 3 ECDIS training objectives.
Section 4 Technical details about ENCs and RNCs. This section explains the benefits of ENCs over paper charts, explains what a ‘SENC’ is, what a ‘RENC’ is and explains the differences between official and private (non official) electronic chart data.
Section 5 Glossary/List of Abbreviations of electronic charting terms, references and relevant IMO Safety of Navigation Circulars.

Note: We recommend that you read the Facts about Electronic Charts and Carriage Requirements to become familiar with electronic charting terms and concepts prior to reading the following information.

What kinds of official electronic charts are available covering New Zealand waters?

Official charts are those issued by, or on the authority of, a Government authorised Hydrographic Office or other relevant government institution. The New Zealand Hydrographic Authority (NZHA) is New Zealand’s national charting authority. It is the only authority that can publish official paper and electronic charts of the New Zealand Charting Area.

What items do I need before I install my service?

Before you start to install your NZ ENC Service you will need:

  1. NZENC ‘Base’ data
  2. NZENC ‘Update’ data and
  3. NZENC ‘cell permits’

You may already have downloaded the Base and Update data at the time you received notification that your cell permits are available for download (within 5 working days of you subscription being received for processing).

Note: If there is no update data available for download, this is most likely because the NZ ENC Service is in a fortnight where a new base dataset has been released. Base data is released six-monthly in January and July. Because base data contains the latest fortnight’s update data, an update data set is not required on base release fortnights.

What do I need to do before I install my service?

Before you install NZ ENCs on your navigation system you should complete the following steps:

  • Step 1 - Check that the S-63 Scheme Administrator certificate is installed on your system.

To use NZ ENC your navigation system must have the S-63 Scheme Administrator certificate’ (IHO.crt) installed. Some manufacturers supply the ‘S-63 Scheme Administrator certificate’ with their software or provide a web-site link to the certificate in their system documentation. To assist mariners who do no have access to the internet whilst at sea, a copy of the IHO S-63 Scheme Administrator certificate is included in the Base dataset. However, if you wish to independently download the IHO S-63 Scheme Administrator (SA) certificate visit the S-63 page of the IHO website

To install the S-63 Scheme Administrator certificate please consult your system manual.

  • Step 2 - Install NZ ENC data

    1. This is the first time an ENC service has been loaded onto my navigation system – what should I do?
      You are ready to start installing NZ ENC on to your System and should not have to remove any previous data and corresponding permits from your navigation system.

    2. I am renewing my NZ ENC subscription– what should I do?
      You can renew your ENC Service subscription in your customer account. As with any new order the new cell permits will be available for download from the NZ ENC Service website.

      If significant time (5 months or more) has elapsed between the expiry of your old NZ ENC subscription and the start of the new subscription we recommend that you remove all previous data and corresponding permits from your navigation system prior to installing the new service.

    3. I already have New Zealand cells installed on my system from another ENC service – what should I do?
      ENCs covering New Zealand Territorial waters are not only included in the NZ ENC Service, they are also included in a number of ENC services offered by the IC-ENC distribution network (such as AVCS). ENCs covering New Zealand Territorial waters will have the same file names regardless of the ENC service – they will all start with “NZ” and have a total of eight characters.

      If you are intending to use the NZ ENC Service in combination with other ENC services and you already have ‘NZ’ cells and corresponding cell permits loaded on your navigation system, most ECDIS systems will handle duplicate cells and permits from different services correctly. The ECDIS should store NZ Cells and permits from the other services separate to the NZ ENC Service. The ECDIS should display the instance of each cell that is most recently updated.

      If you experiencing difficulties in managing permits from multiple ENC services correctly, please email encservice@linz.govt.nz for further assistance.

How do I install my service?

The procedure for loading ENCs (including NZENC) into navigation systems varies from system to system. Depending on your system, you may either have to install all ENC cells from your Base and Update data set or have the option to install just the cells contained within the packs you have a subscription for. Depending on your system and the number of ENC cells to be installed the installation of the Base data may take some time.

For installation instructions, please consult your navigation system manual.

When you subscribe to any NZ ENC pack you will automatically receive a free, fortnightly update service for the duration of your subscription.

Why do I need to update my NZ ENCs?

ENC Updates are the means by which National Hydrographic Offices by which provide mariners with the latest navigationally-critical information applicable to ENCs. It is therefore imperative for all mariners to update their ENCs to ensure they remain safe to use.

Additionally, if you are operating a commercial vessel 12m or more in length engaged in New Zealand domestic operations, most vessels are required to carry up-to-date official nautical charts and nautical publications in order to comply with Maritime Rules for commercial vessels.

The types of navigationally critical information that may be issued as an NZ ENC update includes but are not restricted to:

  • Significant changes to Aids to Navigation,
  • Reports of new dangers significant to surface navigation e.g. shoals, obstructions and wrecks,
  • Changes in general charted depths,
  • Changes in vertical clearances of bridges,
  • Changes in cables and pipelines both overhead and on the sea floor,
  • Changes in prohibited/restricted areas, anchorages etc,
  • Additions and deletions of conspicuous landmarks,
  • Changes to port infrastructure e.g. changes to wharves, reclaimed areas, available depths, works in progress and new port developments,
  • Changes in Pilotage areas etc.

What types of updates are included in the NZ ENC Service?

NZ ENC update downloads contain three distinct components for keeping your ENC packs up-to-date:

  • Changes to existing editions of ENCs, including all permanent, temporary and preliminary notices published each fortnight.
  • Replacement new editions of ENCs when larger volumes of new information have been received, for which you will be sent new permits if the new editions are within the area covered by your ENC data pack(s).
  • Any new ENCs which have not previously existed. You will be sent a new permit if the new ENC is within your subscribed area.
  • Cancellation of ENCs, when an ENC is withdrawn a cancellation update is issued to remove the ENC in the navigation system.

By loading each published update (and any corresponding cell permits) onto your navigation system you can sail with confidence that your NZ ENCs are as up-to-date as possible for navigationally critical information.

How does the NZ ENC Service work in general?

The NZ ENC update Service comprises ‘Base’ data and ‘Update’ data and ‘cell permits’.

  • BASE DATA is released on a six-monthly basis (January and July). At the time of its release, the base data set includes all the ENCs in the NZ ENC series up-to-date to the latest published ENC update. Base data is available, without charge, for download from the NZ ENC Service website.

    Base data set is labelled according to the calendar week the data is released in. For example, an NZ ENC Base released on Friday 10 Jan 2020 will be labelled “Week 02-2020”.
  • UPDATE DATA is released fortnightly, on a Friday. There is one exception - when new base data is released there will be no update data published in that fortnight. This is because when base data is released it contains the latest fortnight’s update data as well. Update data is the ‘top-up’ mechanism by which you can keep your NZ ENCs up-to-date between base data releases. In exceptional circumstances data may be released on the following Monday instead of Friday.

    NZ ENC update data is released on the same Friday as paper Notices to Mariners are released. It is labelled according to the calendar week when the data is released. For example, an NZ ENC update released on Friday 24 Jan 2020 will be labelled “Week 04-2020”. Because NZ ENC updates are released fortnightly, week labels will increment by two (for example Week 04-2020, Week 06-2020, Week 08-2020 etc).
  • CELL PERMITS enable the individual ENCs for which you have subscribed to be viewable on your navigation system for the duration of your subscription. New cell permits will be supplied if we release new editions of existing ENCs already included in your ENC packs, or if new ENCs are added in the area covered by your ENC packs.

    It is important to load the latest set of permits when loading update data. Failure to load the permits corresponding to an update will deny access to new cells released in the update and may even result in access disappearing to previously accessible cells (where a cell has been cancelled and released in the same geographical area with a new file name).

What does the NZ ENC Service offer?

The NZ ENC Service is a free service and automatically provides cell permits for each NZ ENC data pack subscription for its duration. After you have downloaded your initial base and update data from the website, the service also expects you to download subsequent updates and permits from the NZ ENC Service website. You will receive notification emails with a report to advise you of new available updates in your subscribed area.

The process to install ENC data and permits varies between navigation systems so please consult your navigation system manual for instructions. If you are having problems in installing your base and update data sets, refer to the fact sheet Guide to Installing your NZ ENC Service which was attached to your notification email and can also be downloaded from the ENC Service website.

How do I access my NZ ENCs?

If you have downloaded the base and update data you will need to load both data sets and your permits onto your navigation system. If you only have a base data then just load this and your permits. After your registration you should have received a notification email which notifies that permits are available for download. The process to install ENC data and permits varies between navigation system, so please consult your navigation system manual for instructions. You should also read the "Guide to installing NZ ENC' which will be attached to your notification email.

How do I update my ENCs?

Every fortnight the NZ ENC Service will send you a notification email with a report showing if the data pack(s) you have subscribed to have any updates or any new cell permits available for download.

You should wait until you have received your fortnightly notification email before loading the Base and Update data on your navigation system. Failure to load the permits corresponding to an update will deny access to new ENC cells released in the update and may even result in access disappearing to previously accessible ENC cells (where an ENC has been cancelled and released in the same geographical area with a new file name). If your email advises that permits are not available for your ENC packs, just load the Base or Update data.

  • Base data: You will download base data in January and in July, unlike the regular fortnightly update data.
  • Update data: Update data is available for download on the publication day of the paper New Zealand Notices to Mariners (NtM) edition. All NZ ENC update data sets are cumulative, they contain all updates issued since the last base data release and get larger each fortnight. Variations of releasing update data might occur due to public holidays.
  • Fortnightly notification email: Each fortnight during your subscription period the NZ ENC Service will send you an email which will contain an ‘Update Report’ that lists the types of updates issued for your ENC packs

In case of a new edition or a new ENC the permits are available for download from your personal account. In exceptional circumstances the notifications may be sent on the following Monday instead of Friday.

What should I retain for backup purposes?

We recommend you retain:

  • A copy of your latest base data. Previous editions of base data should be destroyed.
  • A copy of your latest (cumulative) update data (which corresponds to your latest base data). All previously supplied cumulative update data sets can be destroyed because the latest update will contain all previously issued updates as well.
  • A copy of your latest cell permits.

What happens when my cell permits expire?

After your cell permits have expired you will no longer be receiving notification emails. You will also not be able to install updates downloaded from the NZ ENC Service website onto your navigation system. Unless you renew your subscription, your data will not be updated for navigationally critical information, will become unsafe and will immediately cease to meet chart carriage regulations.

IHO S-63 compliant navigation systems should issue warnings prior to ENC cell permit expiry to provide sufficient lead time for you to subscribe to new subscriptions. Additionally, you will receive a series of warnings via your NZ ENC notification email which will list the NZ ENC packs with subscriptions that are about to expire. These warnings will be automatically issued 30 days prior to permit expiry.

What else do I need to know about updating my ENCs?

See ‘Updating tips for all NZ ENC users’ at the end of this document.

How do I renew my subscription?

When it is time to renew your subscription, you can login to your personal account and follow the instructions.

Updating tips for all NZ ENC Users
  1. It is good practice to load updates every fortnight, even when you are notified that there aren’t new permits available for your pack. This is because most navigationally critical information is in the form of NtM updates applied to existing ENC, with only a lesser number requiring a full new edition each fortnight and associated new cell permit. If you wish to check whether any updates apply to your packs prior to installing an update, you can consult your update report attached to your fortnightly notification email.
  2. Updates are also used to cancel withdrawn cells. When cancellation update is issued your navigation system may either remove the ENC or allow you to decide to retain the ENC. If you decide to retain it, each time you view the cancelled ENC your system should display a message to warn you that under no circumstances should the cancelled ENC be used for primary navigation
  3. Update data set only corresponds to a particular edition of base data. Therefore you must load updates that relate to the correct base data. Errors will be experienced if updates are applied to the wrong base.
  4. NZ ENC cell permits are specific to a particular fortnightly update. It is important to load new permits and the corresponding ENC update data onto your navigation system at the same time. Loading new permits without the corresponding update data may remove access to previously installed ENC cells. Loading update data without the corresponding permits will deny access to new ENC cells released in the update and may even result in access disappearing to previously accessible cells (where a cell has been cancelled and released in the same geographical area with a new file name).

It is important to load all cell permits notified to you. Failure to follow this advice:

  • Will not enable your system to display any new cells issued for your packs.
  • Will not apply or display future updates to cells replaced by new editions.

ENC are controlled by permits that determine how long they can be used for and by whom.

The majority of ENC publishers encrypt their ENCs using the International Hydrographic Organization (IHO) S-63 data protection standard. All ENCs covering New Zealand waters published by the New Zealand Hydrographic Authority (NZHA) are protected using the S-63 standard. This includes New Zealand ENCs released and incorporated into the IC-ENC service.

What is the IHO S-63 standard?

The IHO S-63 standard has two main components: encryption and authentication.

Encryption is a way to make electronic data readable only to those who are authorised to use them, by means of an electronic ‘key’ called a ‘cell permit’. A data server encrypts the data using a mathematical algorithm called a cipher. The recipient’s key decrypts or ‘unlocks’ the data and making it readable again.

Authentication is the process of verifying, that data has not been tampered with or corrupted in transit between the data server and the recipient.

How does the IHO S-63 encryption work?

In accordance with the IHO S-63 standard, the NZHA provides encrypted NZ ENCs to the mariner with a unique encrypted key for each ENC cell they have subscribed to. These keys are known as a ‘cell permit’ and are unique to each IHO S-63 compliant navigation system. Cell permits also contain information about the duration of each subscription. The mariner loads the cell permits into the navigation system and the system then uses the cell permits to unlock subscribed ENC data to permit access and viewing.

Before the cell permits can be created the mariner must supply NZHA with another encrypted key called a ‘S-63 user permit’. The user permit is allocated by the system manufacturer and is an encrypted key which is unique to each navigation system sold. This is usually supplied with the documentation accompanying the navigation system when purchased. On receipt of a valid S-63 user permit, the user permit can be decrypted, identify the manufacturer of the system and generate encrypted cell permits that will only work on the mariner’s navigation system.

How does the NZ ENC Service work?

At the NZ ENC Service Website customers can obtain NZ ENCs free of charge by registering and subscribing to the Service.

Most importantly, prior to registering with the NZ ENC Service you must check that your navigation system is configured for and compatible with IHO S-63. When subscribing to NZ ENC Service, you must supply your S-63 user permit (as provided by your navigation system manufacturer) and your contact details. The NZ ENC Service will then process the order and make the cell permits available via download from your personalised account at the website, once you have logged in. The ENC data can also be downloaded from the website. The customer will receive fortnightly notifications of chart updates and will be advised if new cell permits are available.

How do I determine if my navigation system is IHO S-63 / NZ ENC compatible?

To use NZ ENCs, your navigation system will need to be IHO S-63 compatible. If your system is compatible your system distributor/system manufacturer will be able to provide you with an ‘S-63 user permit’. If not, your system is not compatible.

In addition, your navigation system should be configured for use with the ‘IHO S-63 Scheme Administrator certificate’.(S-63 page of the IHO website) This certificate relates to the ENC authentication process – see below. Systems configured for use with non IHO S-63 Scheme Administrator certificates may have difficulty loading NZ ENCs. If this occurs, you should contact the NZHA at ENCservice@linz.govt.nz. for assistance.

If I have several separate navigation systems, will I need multiple subscriptions?

A separate S-63 user permit is provided by the manufacturer for each separate navigation system installation/site. For example, a shipping company wishing to use ENCs on five vessels will require (at least) five ENC subscriptions and therefore at least five S-63 user permits.

What happens if I load the wrong cell permits on my navigation system?

Since ENC cell permits will only work with the navigation system installation with the matching S-63 user permit, it is important for mariners with multiple navigation systems to be able to distinguish between systems easily, so that cell permits can be loaded on the correct system. If the wrong user permits are loaded, the navigation system will report an error.

When will I receive ENC cell permits from NZHA?

On first subscribing an NZ ENC data pack the NZHA will make the NZ ENC cell permits available for download within two to five working days of receipt of your system information and contact details.

The NZ ENC Service includes a fortnightly update service for the duration of the 12 month subscription. In some instances the magnitude of the update to an ENC requires that it is published as a new ENC edition of the ENC. Occasionally a new ENC will be added in a particular area to improve coverage or provide significantly greater detail. If a new ENC edition or a new ENC cell has been published within the area covered by your subscribed NZ ENC data pack, then a new cell permit will automatically be issued to you via download from the NZ ENC website. This information can be obtained from your fortnightly NZ ENC Service report, which will include the information about ENC data packs you have subscribed to.

Which do I load first, the cell permits or the ENC data?

To determine whether cell permits or ENC data should be loaded first, you should consult your navigation system manual. Once this has been ascertained, you should remember that NZ ENC cell permits are specific to a particular fortnightly update. It is important to not load new cell permits until you have received or downloaded the corresponding ENC update data. Failure to follow this advice may remove access to previously installed ENC cells. NZ ENC installation instructions are supplied via email at initial subscription and when the subsequent six monthly base data is released. They can also be accessed any time from the Download page.

What happens when my cell permits are about to expire?

IHO S-63 compliant navigation systems should issue warnings prior to ENC cell permit expiry to provide sufficient lead time for you to obtain new subscriptions. It is important to renew your subscription before it expires to guarantee continued access to your ENC data. Once cell permits have expired, it will not be possible to load updates.

How do I extend the duration of my subscription?

The NZ ENC Service offers 12 month subscriptions for every ENC data pack. When you wish to extend your subscriptions, you will need to login to the NZ ENC Service website and renew it.

Can I use NZ ENC Service if I have ENC from other services installed on my system?

You can use NZ ENCs if you have ENCs from other services installed. However, your navigation system may behave unpredictably if ENCs with identical file names have been loaded from two or more ENC services. All ENCs covering New Zealand waters are published by the New Zealand Hydrographic Authority. They are included in the NZ ENC Service as well as in a number of services offered by the IC-ENC distribution network (such as AVCS). ENCs covering New Zealand waters will have exactly the same file names regardless of the ENC service. They will start with ‘NZ’ and have the same coverage and scale. However, because most ENC services sell ENCs in packs, you may not be aware that your pack contain NZ cells.

If you are intending to use the NZ ENC Service in combination with other ENC services, we recommend that you identity the NZ cells that you will receive as part of your subscription and remove any matching NZ cells from other services from your system. This should be done prior to loading NZ ENCs. However before taking this step you should ensure that you have backup copies of your other service’s ENC data and cell permits.

How does S-63 authentication work?

The IHO S-63 data authentication process relies on your navigation system having access to a particular ‘certificate’ which contains a list of S-63 data servers. When you load ENC data (including ENC updates) on to an IHO S-63 compliant navigation system, the system will check that the ENC data is authentic and coded correctly for a particular data server by referring to the certificate. If not, the system will issue a warning that the authentication check has failed.

To use NZ ENCs a navigation system must have access to the certificate called the ‘IHO S-63 Scheme Administrator certificate’ (IHO.crt). Some manufacturers supply the ‘IHO S-63 Scheme Administrator certificate’ with their software or provide a web-site link to the certificate in their system documentation. If you wish to independently download the IHO S-63 Scheme Administrator (SA) certificate the URL is: https://iho.int/en/enc-data-protection

Why is data authentication important?

Mariners using authenticated ENCs can navigate safe in the knowledge that their ECDIS or ECS contains ENC information from an authorised data server and is as the data publisher intended.

What happens if the S-63 authentication check fails?

If the S-63 authentication check fails, your navigation system will issue a warning that you will be required to acknowledge. This will occur prior to loading any ENC data (including updates) in to the navigation system’s internal system ENC (SENC) database. At this stage you can choose to halt the loading process or continue. If the authentication check fails NZHA encourages mariners to contact their ENC distributor. However, if you choose to load the ENC data, the warning will not be re-issued because the navigation system will then convert the ENC data into its own proprietary or SENC format. Once loaded into the SENC, the data that failed the authentication check will be undistinguishable from the other ENC data viewable in the navigation system. Adding non authenticated data to the SENC is potentially dangerous. The decision to do so should only be made after risks are thoroughly assessed as its quality and integrity cannot be assured.

The IHO website provides information on Electronic Chart Display and Information System (ECDIS) software and a list of S-63 compliant Original Equipment Manufaturers (OEMs) (PDF)