Bronzies are the most common large shaek seen in NZ waters. Bronzies are known to steal fish and they can grow upto 4m and they are common in the sounds.
I like this quote from a spearfishing site
“The most common shark in New Zealand waters, the bronzie accounts for 99% of all shark sightings. It is most easily recognized by geography: If you see a shark and you’re diving in NZ waters, it was a bronzey”
I have never been lucky enough to see one but I do not go spearfishing much anymore.