American Morse code standard for U.S. landline telegraph companies, including the dominant company, Western Union, in part because the original code, with fewer dashes, could be sent about 5% faster than International Morse. American Morse also was commonly used for domestic radio transmissions on the Great Lakes, and along the Atlantic and Pacific coasts. However, International Morse predominated for ocean-going vessels, and many U.S. shipboard operators became skilled in transmitting both versions of the Code as needed. As already mentioned, American Morse is less suitable for use on cables because of the high density of dots. However, this same feature, together with the
Morse code This efficiency makes CW extremely useful for DX (distance) transmissions, as well as for low-power transmissions (commonly called "QRP operation", from the Q-code for "reduce power"). The ARRL has a readability standard for robot encoders called ARRL Farnsworth Spacing that is supposed to have higher readability for both robot and human decoders. Some programs like WinMorse have implemented the standard. People learning Morse code using the Farnsworth method are taught to send and receive letters and other symbols at their full target speed, that is with normal relative timing of the dots, dashes, and spaces within each symbol for that