That wasn't my intention - both sightings were from the passage north of the convergence. If anything I guess I was implying that the best chance of seeing this beastie was to be working the relevant waters (in this case the passage, or perhaps sub ant NZ) on a frequent basis.
It looks like their distribution is temperate to sub-antarctic, but they have been seen in Antarctic waters, and are thought to be at least reasonably common and partially migratory (
Source - CMS). One problem with mapping the distribution of a species like this is that there isn't a huge amount of data to work from, and observer coverage is not distributed well across its range.
So - I agree that, at the moment, its impossible to go out and guarantee a sighting of a live one in a short space of time, but I
don't think they are the hardest cetacean to find or identify at the moment - try Hubb's, Andrew's, Ginkgo-toothed...