Trust the Kiwis to come up with some red-hot action adventure in freezing water-filled caves.

Their cavalier, can-do attitude was amply demonstrated in 1987 when a Waitomo guide casually floated through the Ruakuri Cave on an inflatable tube and discovered a unique low-risk adventure that is now legendary.

Black-water rafting (also called cave tubing) involves gently floating through a pitch-black cave with a big rubber inner tube fitted snugly around your waist or bottom. Your first challenge is to jump two metres off a ledge into the inky blackness of the cave. Don’t even think about what creatures may lurk beneath the murky waters.

Waitomo is the main centre for this curious version of rafting, with several commercial guiding companies operating as Black-water Rafting or Tumu Tumu Toobing and there are also combo journeys with names such as Rap, Raft ‘n’ Rock and Haggas Honking Holes, Long Tomo Rafting and Waitomo Down Under.

Limestone caves are common in other Karst landscapes around New Zealand and black-water rafting is bound to spread. Westport has an Underworld Rafting experience near Charleston, which explores the glow-worm studded lower levels of the Metro Cave emerging in the rapids of the Nile River. Greymouth also has options for adventure caving.

So don a wetsuit, hard hat and rubber inner tube and hit the water (the highlight is leaping into the void). Join the glittering glow-worms, old fossils and young free-spirited adventurers and have the time of your life.