U.S. Coast Guard Petty Officer Joel Sayers and hundreds of rescuers like him have spent the past five days saving thousands of lives in the areas ravaged by Hurricane Katrina.
"The Coast Guard itself is basically a service of saving lives and that's the one thing that I've always wanted to do," said Sayers. "When I saw there was a possibility of being a rescue swimmer, it just gave me a great opportunity to get out there and do that."
Hurricane Katrina has given Sayers more opportunity than he ever imagined.
"I wish I had a 747, so could I swoop down there and pick up these people, but I don't," said Lt. Cmdr. Nevada Smith, a Coast Guard pilot.
Even with the mandatory evacuation of New Orleans, an estimated 80,000 people didn't leave the city. The Coast Guard got there as quickly as the weather would allow.
"I didn't think there would be that many people waving at us as we went by, but there's hundreds of people who need help, and we can only hoist so many," said Petty Officer Larry Robinson, a Coast Guard aviation mechanic.
These rescue teams are trained to save people from very different kind of environments.
"We're used to being on big seas and taking people off fishing boats, but this is way different. Now you're taking somebody off a rooftop," said rescue swimmer Scott Rady.
The urban landscape of crisscrossing power lines, contaminated water and desperate people is making the work that much harder.
"The problem is houses with very, very steep roof lines, shingles, things flying off, a lot of debris," said Sayers. "There's just so many different obstacles you run into and so many different dangers."
On Tuesday, Sayers ran into a formidable obstacle.
"One of the first houses we came to had a lady on it," he said. "She immediately told me that her husband was still in the house. She pointed to a small hole, and then informed me that he couldn't walk. So I looked around the house to see if I could knock out a vent and there was no way to get in. The water was all the way up to the eve of the house, and he was trapped in the attic. I couldn't take him under, and I couldn't take him through."
A fire rescue team lent him an ax.
"When I got done cutting through the roof," said Sayers, "I was the happiest man alive because it was hot and I was tired, but the look on his face was amazing."
The Coast Guard has been able to get so many survivors from the disaster area. They can put two swimmers on each helicopter, so they can rescue people twice as fast.
"I lost count after the first day," said Sayers. "Otherwise again there are just so many, pulling people from the water, taking people from the land, medevacs from hospitals. After awhile, you just kind of lose count."
Since Katrina wreaked havoc from New Orleans to Mobile, Ala., the Coast Guard along with the Army and the National Guard has been working around the clock to pluck survivors from the floodwaters.
"I don't think anyone has complained since this thing has started," said rescue swimmer Sara Faulkner. "And you know all of our crews are either at home resting, flying until they can't fly any more, or they're on standby to go out again. And you have not heard one complaint from anybody. I mean, this is what we do."
While giving hope and relief to the desperate, these rescuers have seen unimaginable horror.
"I try not to describe it," said Sayers. "It has been quite a catastrophe and we will just continue to go out and will do the best that we possibly can to make sure we save as many lives as possible."
ABC News' Bob Woodruff filed this report for "World News Tonight."