This reference for all users of the "Global Maritime Distress and Safety System" has been updated since the previous edition. It brings together all the strands of GMDSS, certification, satellite communication, Digital Selective Calling, radiotelex, radiotelephone any many others. Table of Contents Global maritime distress and safety system (GMDSS) distress, urgency and safety communications digital selective calling (DSC) radiotelephony (RT) satellite communications radiotelex (NBDP) radio trsffic general regulations certification special services electronic positions fixing systems.