ECDIS
Electronic Chart Display and Information System. A computer-based navigation system using vector electronic charts, mandatory on most commercially registered yachts above 500 GT.
ECDIS is mandated under SOLAS Chapter V for vessels engaged on international voyages above 500 GT. Type approval requires conformance with IMO Resolution A.817(19). Bridge officers must be ECDIS-trained per STCW Manila amendments. ECDIS replaces paper charts as the primary means of navigation; paper charts may be retained as backup at flag-state discretion.