"Code Alpha" is a secret code used on some cruise ships to indicate a medical emergency onboard the ship. Specifically, "Alpha Alpha Alpha" is the code used on Royal Caribbean Cruise Ships. When this code is announced, the ships medical staff will respond to the call, and passengers should generally go about their day, but those in the area of the emergency should stay out of the way of the first responders. Its important to note that different cruise lines may use different codes for certain emergencies, so its a good idea to familiarize yourself with the codes used by the particular cruise line you are traveling with.