Off on a slight tangent as it is nothing to do with trade, but the POAL website says that HMS Daring will visit Auckland on 17th September for a few days, to be berthed at Princes wharf. This is a newish Destroyer - D 32 - and presumably is on a world tour - it was in Hawaii in July, according to the most recent photo on the site.
On the 16th September HMAS Perth, an Australian Anzac Class frigate is arriving in Auckland, to be berthed at Queens wharf.