This Scratch program uses the international flag alphabet to create messages. Controls: Double-click to clone a flag, letter, or number, then drag-and-drop symbols from the bottom portion of the screen to the sky. Click Sailor Dog to cycle through the plaintext and signal flag displays. Make all the flags larger or smaller using the Scale slider or changing the variable manually in the Stage script. Press <s> to turn the introductory text and music off. Reset using the stop sign and green flag to begin a new message. If you have a message to create, select "plaintext" and drag and drop your message letter by letter to the sky, then click the Sailor Dog to change the display to flag signals. You can then screen capture or transcribe the message you want to share. If you have a message to decipher, select "flag signal" and drag matching symbols from your message to the sky, then click the Sailor Dog to change the display to "plaintext." The hidden content of the message will be revealed.
Image of Sailor Dog from "The Sailor Dog," by Margaret Wise Brown, illustrated by Garth Williams, 1953. Music "Whale of a Tale," by written by Al Hoffman and Norman Gimbel, performed by Kirk Douglas, from the movie 20,000 Leagues Under the Sea, 1954. The International Code of Maritime Signals substitutes letters for pre-arranged flags. In addition to spelling out messages, there are one- two- and three- flag series to quickly communicate with other ships. Navy and commercial ships also use pre-arranged codes signaled by combinations of flags. For further information, the Wikipedia article can get you started-- https://en.wikipedia.org/wiki/International_Code_of_Signals.
