The Digital Cartography Division produces Elecronic Nautical Charts (ENCs)  in S57 Ed 3.1 vector format, according to the IHO International Hydrographic Organization (IHO) specifications.

Only ENCs can be used within Electronic Chart Display and Information System (ECDIS), to meet the International Maritime Organization (IMO) performance standard for ECDIS.

ENC is an official database created by the national hydrographic office for use with an ECDIS; however they can be used by any other capable of reading data in S57 Ed. 3.1 format.

Since April 2004, HNHS has started the provision of the Greek ENCs to the market, as well as their monthly Updating Service, through the Regional ENC Centers (RENCs) www.ic-enc.org   and www.primar-stavanger.org