What could be more terrifying than being buried alive?

The jubilant scenes this week when 33 Chilean miners were freed after two months trapped underground were a reminder of when 7 cavers were trapped in Waitomo.

He could hear their cries for help but it took Peter Chandler hours to locate a group of cavers trapped overnight in Waitomo caves.

The six men and one woman from Hamilton Tomo Group had set off on the morning of July 5, 1986, expecting a day-long expedition through Mangawhitikau Cave. Instead, they spent 15 hours huddled together in a dry, rocky passage above raging rapids that blocked their exit from the subterranean caves.

"They were yelling but it was hard to figure out where they actually were because of the noise of the water," says rescuer Chandler, who owns Spellbound Glowworm and Cave Tours.

Despite spending the night shivering in wet clothing, the group were in good spirits when Chandler finally found them.

The cavers did not have the option to go back the way they came as they had abseiled 30m underground into the cave and they wouldn't have been able to haul themselves back up the rope above what was now a waterfall.

The rescuers' biggest concern was how to get Russell Hall, pictured, up a narrow crevice to Chinamen's Eye, the nearest opening to the cavers' sheltering spot. At 193cm tall, it was a tight squeeze. "Russell was a big chap so getting him out was the main challenge," says Chandler, who ripped the knees and elbows off his wetsuit as he scrabbled along treacherous passageways.

Cavers still venture into Mangawhitikau Cave but because water levels can rise quickly they must be aware of the weather conditions and the possibility of flooding, says Chandler. "It's definitely a cave to avoid in high water," he warns.

Just how dangerous the cave could be was proven again eight years after Hall and his mates were rescued: Carey Phillips, a 29-year-old electronics technician from Otorohanga, was sucked into a surge pool of aerated water and drowned.

Phillips, an experienced caver, was in Waitomo for the 1994 annual meeting of the New Zealand Speleological Society.

"He wasn't a strong swimmer," says Chandler. "He jumped in a pool and didn't come up."