Just off the Kona coast, in arguably some of the state's most pristine waters, a local diver is documenting large sections of underwater pipes that he says are damaging large swaths of coral.

"Those structures are going to fall apart and do incredible damage," said spear fisherman Mark Barville, talking about a deteriorating underwater pipe system.

Barville said he's not the only one who knows about the pipes, but recently he started to take a closer look -- only to wish he'd done so sooner.

"I know what I see. It's not good. It's a junkyard, and not only is it a junkyard, it's a junkyard that's mobile," he told KITV reporter Lara Yamada by phone from the Big Island.

The old pipes sit in waters not far off Keahole Point on the north side of the Big Island -- waters used by The Natural Energy Laboratory of Hawaii Authority or NELHA.

"This is something that happened 20 years ago," began NELHA Executive Director Greg Barbour.

He said a company called Ocean Farms of Hawaii, one of NELHA's first big tenants in the 1980s, went bankrupt and abandoned the pipe system.

He said he became aware of the problem when they dove down into the area to survey one of their own pipelines.

"We're out to bid right now to fix some electrical connection on a submersible pump," he said.

"I thought, one big storm, and the entire pipe structure is going to collapse," said Barville.