This rulemaking would revise existing security training requirements for mariners serving onboard vessels subject to the Standards of Training, Certificate, and Watchkeeping Convention and Code (STCW), to meet certain security training requirements found in the 2010 amendments to the STCW, Chapter VI. Existing Coast Guard regulations already require certification in keeping with the STCW, but the domestic training required for certification under those regulations does not meet STCW standards. Specifically, the STCW requires formal, competence-based training for: security awareness for mariners without designated security duties; and additional training for mariners with designated security duties. The STCW also requires on board security-related familiarization for all mariners on a vessel subject to the STCW.