The Coast Guard, part of the Department of Homeland Security, has made available Revision 9 to the Maritime Security (MARSEC) Directive 104-6. This directive provides important guidelines for U.S. ships operating in areas where terrorism, piracy, and ship robbery are common. Since this information is sensitive, it's not available to the public, but U.S. vessel owners and operators affected by previous versions should contact their local Coast Guard contact for a copy. The new revision also updates high-risk water locations and responsibilities and highlights some changes like reducing electronic vessel transmissions in certain areas.
Simple Explanation
The Coast Guard has made a new set of rules to help ships stay safe in dangerous waters where bad guys might attack. Ship owners need to ask the Coast Guard for these rules because they are secret, but they'll help ships stay out of trouble.