Vector Chart

A vector chart (ENC, electronic navigational chart) stores chart features as layered, object-coded data to the IHO S-57 (now S-101) standard, rather than as a scanned raster picture. ECDIS draws it at any zoom, lets the mariner query an object, and triggers anti-grounding and safety-contour alarms against the ship’s draft. A raster chart (RNC) is a digital photo of the paper chart with no object intelligence. SOLAS V/19.2.10 mandates ECDIS with official ENC coverage on most ships on international voyages.