10 USC 6246 - Navy and Marine Corps Medal
(a) The President may award a medal called the Navy and Marine Corps Medal of appropriate design with accompanying ribbon, together with a rosette or other device to be worn in place thereof
(1) to any person who, while serving in any capacity with the Navy or the Marine Corps, distinguishes himself by heroism not involving actual conflict with an enemy; or
(2) to any person to whom the Secretary of the Navy, before August 7, 1942, awarded a letter of commendation for heroism, and who applies for that medal, regardless of the date of the act of heroism.