Mariners sailing on SOLAS class vessels using an Electronic Chart Display & Information System (ECDIS) can find worldwide coverage of vector charts and raster charts through the Admiralty Vector Chart Service (AVCS) and the Admiralty Raster Chart Service (ARCS). Admiralty digital charts (also known as electronic navigation charts or ENCs) consist of digitized data conforming to the IHO’s S-57 ENC product specification that records all the relevant charted features necessary for safe navigation. Admiralty digital charts also conform to the S-63 1.1 security encryption data scheme that is meant to provide a systematic way to distribute data in a secure and commercially viable manner. These electronic charts are required by SOLAS Chapter V, Regulation 27 for all SOLAS class vessels. Non-SOLAS class vessels that are not required to have an Electronic Chart Display & Information System (ECDIS) on board can select Garmin, Navionics, Nobletec, or Rosepoint Electronic Chart System (ECS) products for digital navigation as an alternative to nautical charts.