What are Electronic Navigational Charts (ENCs)?
Below we give an overview of ENCs and a simple description of the flow up to signing a contract.
In the broad sense, ENC refers to navigational charts that have been digitized so they can be displayed on a computer screen. There are two types of electronic chart data: (1) raster charts, which convert paper nautical charts into digital images; and (2) vector charts, which quantify the chart coordinates (latitude and longitude) to create a digital image. Charts made with the later method are called Electronic Navigational Charts (ENCs).
ENCs produce the content of paper navigational charts base on the S-57 format*1 prescribed by the International Hydrographic Orgnazation (IHO).
ENCs may include supplementary information in addition to the information on paper charts that is useful for safe navigation. They are produced by national hydrographic offices, which are government organizations. In Japan, they are issued by the Japan Coast Guard.
Each area of ocean on an ENC is called a cell and is a rectangle delimited by latitude and longitude. A dedicated Electronic Chart Display and Information System (ECDIS*2) is needed to display cells, and the system can only be used by obtaining a license for the regions (cells) you wish to use.
Cells come in five types of data depending on the navigational purpose, ranging from Harbour, which have a zoomed-in view, to Overview, which have a zoomed-out view.
Enhanced convenience such as the following can be gained through combination with an ECDIS:
Plotting of your ship’s position, warning of impending danger en route, superimposition of radar images, automatic scrolling of charts, automatic loading of needed charts, enlargement/reduction of displayed data, storing/retrieval of sailing records, etc.
Types, contract periods, and price
ENCs are produced by hydrographic offices worldwide.
In Asia, ENCs are produced by Japan, Indonesia, Malaysia, Singapore, and other countries. A product called Primar integrates ENC data from each country.
The contract fee is determined by the types of ENCs, number of units, and contract period. You may choose a 3-month, 6-month, 9-month, or 12-month contract, but you cannot choose different contact periods for each ENC.
Additional areas, etc., may be added later, but how this is handled depends on the remaining period of the contract.
Procedure for starting/renewing a contract
The following device/data are needed to use ENCs:
|1. A dedicated ECDIS (must be purchased separately from an ECDIS manufacturer)|
|2. User permit (a 16 digit code provided by the ECDIS manufacturer)|
|3. Cell numbers for the areas you wish to use (these are chosen by referencing websites and catalogues, etc.)|
We will give you a quote once you provide us with the information relating to the above three items. After signing a contract, we will complete the procedures to enable you to use the charts.
We will provide the data on CDs and give you the cell permits at the same time. The cell permits are a key needed to unlock the copy protected (encrypted) data on the CDs. You can use the charts by installing the data and cell permits (provided with the CDs) to your ECDIS.
For safety, the most up-to-data nautical chart data must be used. For that reason, updated data is released generally every week.
Note: Japanese ENCs are issued once a month.
Updated data is provided by forwarding CDs or by downloading from INT. There is no charge for the updated data itself (it is included in the contract fee).
1. Charts are now distributed in the S-63 format. The S-63 format is S-57 formatted data that has been encrypted (to prevent unauthorized copying) according to the S-63 standards.
2. An ECDIS is a devise that complies with performance requirements specified by the International Maritime Organization.