dingy737 - the maritime distress frequency is 2182 on SSB and/or as Red Plum says VHF "channel 16" which is 156.800. A transmission on 2182 or Channel 16 will generate an alert response from automatic equipment. Our EPIRBS transmit on 121.5 but more importantly on 406 for Cospas-Sarsat. Basically we now use Inmarsat for almost all coms except line of sight. Radio officers disappeared about the same time that flight engineers did!
edited to add - cross posted with Ionagh who is precisely correct!
Last edited by Methersgate; 25th Mar 2014 at 14:37.