It was a real slap in the face for a kayaker who got caught up an almighty fight between a seal and an octopus on New Zealand's South Island.

Kyle Mulinder, a New Zealander, was testing out new GoPro HERO7 equipment with some fellow kayakers off the coastal town of Kaikoura.

He said he saw the animals thrashing about for a while, but then he unexpectedly became part of the action.

The seal suddenly threw the octopus into the air, smacking Mulinder square in the face.