When the crash comes which is anyones guess as it might be 3-4 years away just make sure that you have a stop loss in place so that you exit everything then wait and watch because everything will get hammered due to market psychology as fear will prevail for a period of time.
Then evaluate everything and go from there.
It might be the case that Gold and silver might be bad investments after that for quite a while and we might find better opportunities elsewhere.
Just don't assume that AUD Gold will be your immediate safe haven in a crash as you will find that you will be taken down in that as well.
I don't think that we will have to worry about this for quite a while though.