CE has been struggling with a rating system for a decade now, the system is supposed to have some relationship to seaworthiness. However several A rated yachts have sunk in conditions that were moderate, keels fallen off, etc,; while there are examples of yachts that could never get an A rating having circumnavigated without incident. It is a typical government standards body, complicated by international politics.

To answer the question more directly, CE category A is defined as:

"A. OCEAN: Designed for extended voyages where conditions may exceed wind force 8 (Beaufort scale) and significant wave heights of 4 m and above, and vessels largely self- sufficient. "