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.