If you set up your HH with a separate MMSI than your main radio, you can go on line and change the description of the boat each time that you go out in a different one. It is a PITA, but the idea is to let the GC know what they are looking for in case you can't communicate with them.
They are still trying to figure out proper regulations for HH DSC radios. The problem is that all participating countries have to agree. Some don't like the idea of registering a radio with a person rather than a vessel.