SSB has a much greater range than VHF because it does not require a line of sight between stations. Transmitting on SSB requires a great deal of electricity compared to VHF, however, since its signal must be strong enough to travel over great distances through a lot of atmosphere. Satellite communication Satellite communication is a relatively new alternative for long-distance communication. Instead of transmitting an analog signal directly from the vessel to a shore station, a digital signal is transmitted upward to a satellite. The satellite then relays the signal to another satellite or to a receiver elsewhere on the surface of the earth.
Satellite communication is private.
When you use conventional SSB or VHF, everybody with a receiver in range can monitor your conversation. Signals transmitted for satellite communication, however, are highly directional, making them much more difficult for the casual eavesdropper to pick up. In the case of digital signals, data can be encrypted, making it extremely secure against even a determined spy. Satellite communication is not greatly affected by atmospheric or meteorological conditions. Because the signal is being transmitted primarily upward, it passes through a relatively thin layer of the Earth's atmosphere.