In the most recent Wavelength, there is an article about "Calling the Coastguard using DSC" on Page 8.
The article explains that you should key in the Coastguard Station MMSI number - then make the "routine call" - and wait until your set displays the channel chosen by the Coastguard. It goes on to say "it is the CALLER WHO SPEAKS FIRST". In other words, if the Coastguard indicates 67 as the channel you should go to 67 and call them.
All of this is completely correct, but as an ex-coastguard who still has friends working in the ops room, it would have been better to have added just a little bit extra as follows:-
Call the Coastguard on the indicated channel - but use the format "Solent Coastguard this is Mucky Duck MMSI 234001234 over".
The addition of the MMSI number to the call immediately tells the MRCC unit that you are responding to their MMSI transmission. Your boat name alone DOES NOT do that as at present there is no automatic link for the Ops Room between MMSI and Boat Name.
Hence it makes the Coastguards life just a little bit easier, and they will appreciate that