The amateur service is the oldest radio service and pre-dates regulation of radiocommunication. The original reason for regulation of the radio spectrum was to improve maritime safety and to ensure that coast stations would communicate with all ships, not just those using their company’s equipment. In 1912, amateurs could use any frequency above 1.5 MHz, as they were regarded as “of no commercial value for maritime, governmental and commercial communications”. However, the value of the higher frequency bands was recognized in the 1920s. Today, the amateur service retains relatively narrow bands throughout the entire radio spectrum. These bands provide the whole range of radio wave propagation mechanisms and, through experimentation, amateurs have contributed to the understanding of propagation.