Keeping Your Charts Up to Date - Part II - Regulations

Regulations & Interpretations

Before July 2002 SOLAS Chapter V Regulation 20 stated that All ships shall carry adequate and up-to-date charts, sailing directions, list of lights, notices to mariners, tide tables and all other nautical publications necessary for the intended voyage.

There was no distinction between private and official charts. As long as there were paper charts SOLAS did not feel the need to protect mariners from ‘private’ charts. The cost of a paper chart is heavily subsidized so private companies cannot compete with government here.

Digital charts were started in the eighties by some private entrepreneurs. It was targeted towards the light marine industry. With the advent of electronic charts in the nineties SOLAS felt the need to amend the regulations in order to protect the mariners.

In 2002 a nautical chart was redefined as one issued under the authority of the government. Under the current SOLAS regulation all ships must carry nautical charts and publications necessary for the intended voyage which are adequate and up to date. Thus the official and private charts came into being.

Carriage of Goods By Sea

Most countries have adopted the Hague rules or the Hague-Visby rules to stipulate the carriage of goods by sea. Under Hague rules a vessel must be equipped with up-to-date charts and notices to mariners. Charter party agreements between the carrier of goods and the cargo owner contain the seaworthiness clause. It implies that if a commercial ship does not have up-to-date charts and notices then she is not seaworthy. This makes it liable to be ‘off-hired’. Considering that charter rates run into thousands of dollars per day, this could result into a big loss for the concerned party.

Note, under the Hague rules there is no differentiation between an official and a private chart. 

What is an up-to-date chart?

To a second mate appointed as the Navigating officer up-to-date means charts corrected to the notices that he has received on board. Even today many ships receive their updates by post. Sometimes the NtM packs are more than two months old before they reach the ship. Today some chart agencies use email or radio broadcast to promulgate the notices. This has improved the situation tremendously. 

To the HO up-to-date means up to the notices that has been promulgated via the NtM booklets or as Navarea warnings/ Navtex/ EGC messages.

How are digital charts corrected nowadays?

Let us see how C-Map does it. At C-Map headquarters they receive chart corrections from contracting hydrographic offices all over the world. They come weekly, fortnightly or at other regular periods. At the headquarters the updates go through quality control and are checked for consistency. Once they are tested and have passed the quality control the updates are made available to the user via a server.

Individual users access the C-map servers from the internet. Each user is checked for validity and their present status of chart database. The customer is then allowed to receive the charts corrections in the binary format. Typical size of chart correction for a world database of about 22000 charts is about 50Kb for one week of corrections. It can be easily downloaded onto the customer’s system. It is a well proven system and has been running now for many years without a hitch.

The service is available on all major satellite service providers such as Iridium, Geonet and Inmarsat. Those ships who do not want to use online system because of high cost or virus threats can avail the email attachments facility.

Online Updating of Digital Charts

Prior to downloading updates, it is possible to estimate the size of the data that will be received.

Updating via E-mail

For applying the updates using the E-mail service a request for updates has to be sent to the service provider.

The server automatically generates updates for your databases and sends a reply in about 5 minutes. If the size of updates exceeds your requested e-mail size, you will receive several e-mail messages, each of which does not exceed the requested e-mail size.

The next step is to apply the updates to the chart database. Facility is provided to review the updates in the list of updates.

The list on the right part of the panel displays a four level directory tree.

The first level of the directory tree is the list of hydrographic offices that have issued the received updates.

The second level is the list of chart numbers or corresponding datasets to which the updates have been applied.

The third level is the list of update files containing the updates (the third level entry consists of the update file number, update file issue date, and system ID of the update dataset).

The fourth level is the list of updated objects. The list entry consists of the name of the object and short description of the correction. It does not contain the past and present cartographic object position; for example, if coordinates of an object were changed, it is just marked as “Moved”.

Reviewing Chart Updates

There is a possibility to select a single dataset (electronic chart) and then review the changes in each subsequent incremental update.

The chart data (chart number, source hydrographic office, issue date, and last update date) can be displayed in the Picked chart window of the Chart Updates functional panel and the list of updates (the books (update files), in which the corrections were published, with corresponding issue dates) for the chart can be displayed in the Last 10 Updates window.

Figure - Highlighting the Updates on a chart.

Chart corrections add to the price of a chart. In order to reduce the prices there is a different system for the non-SOLAS class. For example the light marine class which falls outside the SOLAS regime can decide for itself how often they need to have the chart corrections.

The chart service providers sell charts updated to a particular date. New updates are brought out typically every 6 months in areas which see frequent changes. It is left to the end-user to decide when to replace their charts. Here the market forces decide the price and volume of sales.