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How to Send a Rescue Signal by Semaphore

The semaphore flag-signaling system is an alphabet-based system that requires waving a pair of hand-held flags in particular patterns. Here's how you send a rescue signal using the flags.


  • Step 1: Get the receiver's attention Get the attention of the person you wish to send the signal to by waving both of your flags repeatedly overhead in a scissor-like motion.
  • Step 2: Wait for acknowledgment Wait for the receiving party to send the semaphore letter K with their flags. This is the signal to proceed.
  • TIP: There are unique flag positions for each letter of the alphabet.
  • Step 3: Transmit N-C Transmit the letters N-C using your semaphore flags. Move directly from the N position to the C position without stopping.
  • TIP: In the International Code of Signals the letters N-C stand for "I am in distress and require immediate assistance."
  • Step 4: Bring your flags down Bring your flags down in front of you with the flag staffs crossing each other after you have finished.
  • Step 5: Wait for acknowledgment Wait for the receiver to send the letter C, acknowledging your distress call. If your message was not received, they will send the letters I-M-I. If this happens, resend your message.
  • FACT: The International Code of Signals was drafted in 1855 by the British Board of Trade.

You Will Need

  • Semaphore flags
  • Receiving party
  • International Code of Signals (optional)

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