for the record:
GUARD and 121.5 are not the same thing.
On a set that has a Guard channel, any frequency can be selected to be guarded. Usually, it is 121.5 or 243.
All the twits who call out "Guard...!!!' when they hear someone transmitting on 121.5 are just as ridiculous as thoe ones doing the chattering.
As for Aust vs Asia (and beyond), you've got to be kidding me right??? The biggest worry in Aust is listening to someone calling Ops on the wrong set.
In Asia, ME, Africa, you are listening to every man and his dog discussing weather, ride, relays, repeated relays, confirming the relays, advising success of the relays, thanking for the relays, saying your welcome for the relays, etc etc etc.
Don't even START with the aussie/121.5 crock, puh-lease!!
PS If you fly in Australia, you don't know how bloody good you have it. Try flying around Africa or Asia and you will find what you used to think worth whinging about in Aussie will become a breath of fresh air.