CM93 v2 charts are a proprietary vector format developed by C-MAP . They are structured as a collection of subdirectories (typically 144 folders) covering the entire globe in 40° x 40° geographical "cells".
Official updates for CM93 v2 largely ended around 2011–2014, making them "obsolete" for primary navigation in modern ECDIS systems. Software Compatibility cm93 v2 charts download
A complete set provides worldwide coverage in a single database. CM93 v2 charts are a proprietary vector format