This manual is designed to help mariners to understand and get the best from radio and satellite communications. It explains the way radio and satellites work and the way the radio frequency spectrum is divided up, internationally and nationally, amongst the multitude of service providers and users. The book covers intership communications, port-harbour and ship movement services, radio telephone and radio telex services, and maritime business (private) radio channels. Also, broadcast services, including distress and safety facilities, weather and navigation warnings, weatherfax and even piracy warnings. Alternatives to the normal global marine radio services, cellular systems (maritime and land mobile systems used by mariners) and the use of amateur radio in the "maritime mobile" environment are also explained. The author spent 12 years as a radio operator in the Royal Navy, both ashore and afloat. He is a fully qualified Merchant Navy Radio Officer and worked in a UK coast radio station for eight years before moving to Maritime Radio headquarters in London.