A new application of synchronous satellite communications technology was unveiled in 1976 with a three-ocean maritime satellite system providing telecommunications services in the Atlantic, Pacific, and Indian Oceans. The Marisat system introduced a new communications capability, providing service in three different frequencies simultaneously--ultrahigh frequency (UHF), L-band , and C-band. UHF frequencies are used by the U.S. Navy communication links between shore and shipboard terminals and the satellites. Commercial maritime services include voice, teletype, facsimile, and high speed data. L-band frequencies are used for commercial communications from ship to satellite. The C-band frequencies are used for commercial communications links between the satellites and Earth stations on each coast of the United States. Satellite tracking, telemetry, and command functions also are conducted over C-band frequencies.