Electronic Navigational Chart (ENC) is an official marine vector navigation chart for digital platforms; which has been standardized by the International Hydrography Organisation (IHO) by the means of range, content and data format (S-57) and has been produced by the related country's official department of navigation, hydrography and oceanography.
These features distinguish the ENC from any other vector map and do allow the use instead of any printed map. ENC is a GIS database and chart related data is stored in this database as forms of points, lines and areas. This structure allows the ENC to be smart and dynamic. The ENC structue is smart because it can be queried and displayed on the screen allowing to handle the needs of the user; and it is also dynamic because it can be updated with small ENC update files.

The authority of producing and updating the marine charts of Turkey is the Office of Navigation, Hydrography and Oceanography - also known as ONHO. Besides its ongoing production of paper charts; ONHO has started producing ENC maps of Turkey since 2001; after completing the related technological investments and funding. The ENC maps produced were initially only used by the Turkish Naval Ships. After a period; by the help of the suggestions of the International Maritime Organization (IMO); ONHO has also become a member of the IC-ENC (which one of the two global collectors & distributors of the ENC maps. The other one is PRIMAR). IC-ENC has been in a position of a sales-agent of ONHO, as well as other countries' departments of Navigation, Hydrography and Oceanography. IC-ENC and PRIMAR do implement a security mechanism called S-63 for encrypting the ENC map data (S-63 = Encrypted S-57 data). These S-63 maps are distributed globally by either of IC-ENC or PRIMAR's worldwide resellers for use with the mandatory ECDIS systems installed at various large gross-tonaged ships.

Electronic chart production requires a high-cost investment. It is also a known fact that; not only producing a chart is enough to use within our current environmental aspects; the charts should also be updated on a regularly basis. In this manner, ONHO's fleet regulary scan the Turkish waters and publish periodical map updates for the Turkish waters; as all other countries' hydrography offices do.

It was a huge loss that the S-57 format ENC maps were only commonly being used within the highly costed ECDIS systems on huge / commercial ships. Targeting to present these valuable vector charts to the leisure marine market and end-users; Doga Teknoloji shared its thoughts with the Turkish ONHO. The project goal was to have a bundled package of software (developed by the national company Doga Teknoloji) and maps (produced by Turkish ONHO) and have it delivered within a secure encryption scheme. Obtaining the ENC maps from the IC-ENC organisation was rather costly and a long-way for the model. Following the application procedure and some technical and operational verification; Turkish ONHO has approved Doga Teknoloji as its first national ENC sales agent on 27th of November, 2007.

ENC maps are produced by ONHO; however; due to the copyright protection precautions; these electronic maps are distributed only by its agents; there's no direct sale of ENC maps from Turkish ONHO. Also; the ENC sales agents of ONHO (such as Doga Teknoloji) are only authorized to sell the ENC maps bundled and encrypted with the agent's own copyright protection mechanism and navigation software (SeyYar+encrypted ENC maps bundle). The agents do not have the right to resell the ENC maps in original, unencrypted S-57 format. Since the encryption progress is a complicated architecture; ONHO chose to outsource the development and control of the ENC copyright security model to its ENC sales agents.

Distribution of the weekly updates issued by the ONHO is also a complicated progress. ONHO also outsourced this responsibility to its sales agents which are qualified for establishing and operating the online internet update backbone.

[ Click here to download the full ENC catalog of Turkey (ZIP file; approx. 21MB) ]