Sea Skills: Communication

During the Second World War, ships often had to stay radio silent. Wireless sets could give away a position, messages could be intercepted, and sometimes equipment simply failed. Sailors still had to talk to each other – to warn of danger, call for help, or keep a convoy together – so they relied on visual communication: flags, flashing lamps, and semaphore.

This interactive “signal station” lets you type a message and see it three different ways: Morse code, semaphore, and International Code of Signals flags. It is inspired by the real skills used at sea in WWII, and it is a chance to see how much information you can send without saying a single word.

Your mission

Imagine you are part of a small escort vessel in 1942. Your radio is out, the weather is closing in, and you need to warn the nearest ship about danger ahead without drawing attention.

1. Choose a short, clear message – for example: SUBMARINE AHEAD, NEED TOW, or SAFE TO ENTER.
2. Type it into the box below and see how it looks in Morse, semaphore, and signal flags.
3. Grab two small flags (or bits of paper) and try to send the semaphore version to a friend or classmate.
4. Swap roles and see how quickly you can read each other’s messages.

Communication at sea is still a vital skill today – from safety messages and navigation to coordinating rescues. Learning how it worked in wartime gives us a better understanding of the decisions and risks sailors faced, and keeps those skills and stories alive.