The rating of a Navy Signalman (SM) was one utilizing visual (silent) communications skills such as the use of Semaphores, signal flags or by Morse code with the use of a flashing signal lamp. The Signalman's job skills also required the ability to send messages via International Morse code over radio signals, knowledge of all of the flags and pennants used in the Navy, and the meaning of international flag hoist combinations. The Signalman was vital to security during periods of "radio silence" in making communications from ship to ship or ship to shore.
With the Signalman App you can learn the basic skills of the U.S Navy Signalman. Five separate functions allow you to transmit and receive messages while learning the basic skills of a Signalman. You can silently send messages to friends over short distances (e.g. across the room) by semaphores, signal light, signal flags or with an audible Morse code signal.