s at sea no longer need to be equipped with Morse-based alarm systems with SOS signaling as in the past. Since 1999, indeed, the regulatory alter- native is now the Global Maritime Distress and Safety System (GMDSS), which uses satellite and other communication principles. 10 The Morse code still has fans world-wide, who collect and use old machine and even organize High Speed Telegraphy Championships. 8.3 The Morse code Table 8.2 Correspondence of the Continental International Morse code with alphanumerical characters, punctuation, and other command characters. The nine letters most frequently used in European languages are placed at the left. call T error end M end B call T = call to transmit, end M = end message, end B = end broadcasting. European languages, i.e., E, T, A, N, I while the longest symbols are attributed to the least frequent letters, such as J, Q, X, Y, Z. In this way, operators save lots of time when generating or writing down Morse codewords. Another trick in the Morse code is that letter symbols take a maximum of four dit/da characters, while number symbols are exactly five characters long. This makes it easier for operators to distinguish between letters and numbers, and avoids any risk of confusion for numbers (mistakes in numbers having potentially more important consequences, unlike with letters, which can be intuitively corrected, or whose mistakes are immediately noticeable). The Morse code has proven quite efficient for rapid messaging between "human entities" having limited telecommunications equipment. Certain civilian and military boats still carry on-board Morse machines as light guns: in adverse conditions when the radio is down because of power failure or enemy scrambling, a point-to-point and "radio-silent" Morse communication by day or by night may be the only solution. And even a small piece of mirror with the sun or a flashlight works very well to communicate over distances of kilometers, and can be included as part of any survivor's equipment, for vital SOS messaging. The Mo