Before radios, phones or computers, sailors on ships needed to be able to communicate with each other.  Messages could be sent between ships that were visible to each other using flags with symbols to give an indication of whether they were in need of help, had sickness onboard or what their intentions were. A system, a code, of international maritime signal flags was developed so that ships from different countries could understand each other.  It’s almost like having a common language.   

Some of the ways the flags were used were to:

• Have a series of flags spell out a message, each flag representing a letter.

• Individual flags have specific and standard meanings; for example, diving support vessels raise the "A" flag indicating their inability to move from their current location because they have a diver underwater and to warn other vessels to keep clear to avoid endangering the
  diver(s) with their propellers.

• One or more flags form a code word whose meaning can be looked up in a code book.

Here’s a fun fact:  the flag called the blue peter is blue with a white square in the centre.  It is flown to signal that a ship is ready to sail. This was chosen to represent the CBBC show Blue Peter because it would symbolize getting ready to sail for adventure and discovery.

Can you make a string of flags that spell your name?

Use this chart to find the letters of your name. The word that follows the letter is known as a phonetic alphabet so that distinctive words can be said to sound out letters.  If someone said Oscar, Bravo, Alpha, November they were spelling out the word OBAN. See the example at the bottom of the page.