A Review of the Relationship of the ENC and DNC Hydrographic Vector Data Products

This document discusses the level of harmonization between the S-57 and DIGEST standards and the relationship between the ENC and DNC products. It is shown that the military and regulated commercial navigation have different needs, and that it is natural to have two different standards. However, in those areas where the needs overlap the standards should be equivalent. Commercial navigation requires "official" data whereas the military require a broad range of the "best available data". These needs are complementary. At the content level ENC data can be a pure subset of DNC data, however additional harmonization is required to achieve this.