No, you don't have to be in a closed garage to die from carbon monoxide poisoning. It's just as deadly out on the open water, CBS News National Correspondent Hattie Kauffman reports.
"Fun in the sun" can turn fatal in an instant. Unknowingly, four boys who were teak surfing, riding the waves behind their boat, were breathing carbon monoxide, the scene was caught on tape.
Stacy Beckett, 17, tried teak surfing. In seconds, she was dead.
Her mother, Sheri Beckett, says, "It's very hard to look at her pictures, because we miss her so much."
Stacy just vanished into the water, her mother says, "The kids thought nothing of it, because you just let go when you're tired, and then the boat comes and turns around and picks you up. Well, she was nowhere to be found."
When Stacy's body was pulled from the water, she had a carbon monoxide level in her in blood of 64 percent. Anything above 25 percent is fatal.
Jane McCammon, an investigator from the National Institute of Occupational Safety And Health (NIOSH) notes, "A typical boat engine puts out the equivalent exhaust of 188 cars."
You don't even have to be on a boat to be overcome. When boats are bunched together in a small space, the very air can become deadly. Last summer, Mark Tostado was poisoned while standing in waist-deep water in a busy boat channel in Lake Havasu, Ariz.
His sister, Beverly Ross, says, "The medical examiner, when I talked to him, he said with the percentage of carbon monoxide he had in his system, that he passed out and was not able to save himself."
She notes her brother had approximately 40.7 percent of carbon monoxide in his body.
After Mark Tostado's death, carbon monoxide monitors were installed in the Lake Havasu channel. Twice during the Memorial Day weekend, the channel had to be closed because levels got dangerously high - precautions that came too late for Tostado's family.
Sobbing, Ross says, "He was an Army reservist, he just succeeded at everything he ever did. To lose somebody that was just there for me all the time, it's so hard."
In California, a bill is moving through the legislature that would require boats with in-board motors to display stickers warning of the dangers of carbon monoxide poisoning.
At a hearing, Sheri Beckett testified, "We searched for Stacy for, like, 15 hours in the water, and finally, she floated up."
The bill would also ban teak surfing. Among those testifying is Mike Farr, a father who'd taught his son, Anthony, to ride the waves behind the boat.
He says he had no idea what he was teaching his son. "Absolutely not. What father would teach their kid something that would take their life?" he says.
Anthony and his family were at Folsom Lake in northern California, enjoying a day on the water, and never imagining the carbon monoxide levels behind the boat could get so high - that just three breaths would be fatal.
Farr notes, "It was usually something that we always did at the end of the day, coming back to the dock. Every single day, and I'd never experienced or any type of headache or any type of poisoning."
Not surprising to Dr. Robert Baron, an expert on carbon monoxide boating deaths. He says there's often not time for symptoms to show.
He explains, "You'll go from feeling something's wrong to, seconds later, being unconscious."
There are more than 500 documented carbon monoxide poisonings since 1990. Experts believe the number is far higher since often deaths are simply classified as drowning.
Dr. Baron says, "Absolutely. It's an under-reported problem."
The numbers are staggering. In the work place, 200 parts per million is considered unsafe, and 1,200 parts per million pose an immediate risk to life and health. Carbon monoxide levels behind boats have been measured at 26,000 parts per million.
McCammon says, "I think that the key to preventing these deaths is engineering control, reducing exhaust at the source."
The National Marine Manufacturers Association is addressing the problem by attempting to redesign inboard engines.
Monita Fontaine of the association says, "We have our best engineers working on trying to develop a marine catalyst like the automobile industry did to solve its carbon monoxide concerns."
But it comes too late for parents like Mike Farr. He says, "It's not like I'm an anti-boat guy at all. I love boats. But they never told me about the dangers of carbon monoxide behind their boat. That's the most frustrating thing, and I'm extremely angry about that."
In the meantime, boaters beware. Just because you're in good shape or a strong swimmer doesn't mean you're safe. One of the vigorous young boys died from carbon monoxide poisoning shortly after the video was shot, Mark Tostado was a fitness instructor; Stacy Beckett, an avid soccer player.
"I just can't believe that she's gone," Sheri Beckett says, crying. "It's just so hard for me, still. It's like, you try to be strong, and I just miss her so much."
The swim platform on the back of the boats with inboard motors is the most dangerous spot to be in terms of carbon monoxide poisoning. Sadly, that's where kids are most likely to hang out and play. It's also where people often sit and videotape their families having fun behind the boat.
The bill outlawing teak surfing in California has passed its first hurdle. It's named for two young victims, Stacy Beckett and Anthony Farr.