A Continuous Certificate of Discharge or Continuous Discharge Certificate (C.D.C.) is a seafarer's identity document. This document certifies that the person holding this is a seaman as per The International Convention on Standards of Training, Certification and Watch keeping for Seafarers (STCW), 1978, as amended 1995. Every seafarer must carry this document while on board, which is also an official and legal record of his sea experience. The master of the vessel signs the document each time a seaman is signed off from the vessel certifying his experience on board.
A C.D.C. granted under STCW rules is valid for ten years and may be renewed on expiration or within six months prior to date of expiration, on a request from the holder, for a further period up to ten years at a time if the holder is a serving seaman and his C.D.C. has not been cancelled, withdrawn or suspended under these rules. If the period of validity of CDC of a seamen expires during the voyage, it is valid until the end of the voyage.