Gilbert Dewey Gaedcke III, 41, was rescued Friday afternoon after a teenager on a helicopter tour spotted him stumbling across the rocky lava, trying to attract attention with a mirror from his camera.
Gaedcke had been missing since Sunday night, when he decided to take a hike across desolate lava fields near Hawaii Volcanoes National Park to get a closer look at an active volcano.
The experienced hiker from Austin, Texas, said he saw no water, but there were pockets of jungle-like vegetation sprinkled throughout the old lava flow.
Gaedcke said he crawled beneath the vines and lick moisture off leaves. Then he found moss growing on trees, and was able to squeeze enough water from it to drink.
"It was muddy, green, mossy water, but it worked," he said Saturday. "If I hadn't found that I'd be dead right now," he said.
Gaedcke said tour helicopters had flown overhead all week, but he was unable to attract attention because clouds blocked the sun.
Then, late Friday afternoon, another one flew over. Aboard was 15-year-old Peter Frank, who spotted the odd glint in the late afternoon sunlight.
"It was the only thing like that out there," said Frank, of Pasadena, Calif. "As we got closer we realized it was a man."
Gaedcke, dehydrated, but otherwise OK after surviving five days in the heat, was lost amid acres of blackened volcanic rock.
"I wound up on some of the most vicious terrain I've ever seen," he said as he rested at a friend's home before flying home. "It's all gray rock — terrible stuff — then vegetation like an oasis, then more gray rock."