A deep-sea canyon just offshore brings sperm whales within sight of the South Island coast year-round.
Kaikoura's whale-watching draw comes down to geography: the Hikurangi Trench runs close to shore here, dropping to over 800 metres within a couple of kilometres of the coast, which pulls squid and other deep-water prey — and the sperm whales that hunt them — much closer to land than almost anywhere else on earth.
Resident male sperm whales can be found here through the year, diving for up to an hour at a time before surfacing to blow and re-oxygenate for the next descent, and the same trip often turns up dusky dolphins riding the boat's wake and, in season, migrating humpbacks.
Book a morning trip when the sea is calmer and visibility better, and don't expect a full breach — most sightings are the surfaced whale blowing and arching before a deep dive, over almost as soon as it starts, so keep a camera ready rather than buried in a bag.
