John Nyberg, Colby Harmon, Dr Shachak Pe'eri, Sidney Catoire,
AN OVERVIEW OF THE NOAA ENC RE-SCHEMING PLAN,
The International Hydrographic Review,
Volume 24,
2020,
https://ihr.iho.int/articles/semi-automated-generation-of-depth-contours-for-encs-2/,
Abstract: The scheme (or footprints) of NOAA Electronic Navigational Charts (ENCs) are based on traditional paper/raster charts from which they were derived. As a result, modernizing current ENC coverage to improve the way they are displayed in a 
digital environment, increase their level of detail, and incorporate additional survey data outside of the existing bounds is complex. As part of NOAA’s “ENC-First” 
effort, a re-scheming approach was developed to provide a seamless, tiled 
coverage that can easily be segmented or extended based on geographic location, available data and scale. In this new regular gridded ENC coverage approach, fewer than a dozen chart scales are used (down from the current 130 scales used in the paper chart scheme). The re-scheme plan also aims to improve products for mariners who prefer paper charts. The uniform scales will enable mariners to 
create customized charts with a new online application. Additionally, NOAA has created one production line for both ENC and Raster Navigational Charts (RNCs) products that will reduce production resources for maintaining two chart products. 

Key Words: Electronic Navigational Charts; Re-scheme; Marine Navigation; Chart Production; Production; Electronic Chart Display and Information System.