greenturtle
06-23-2008, 04:25 PM
Thought this is good info to share, wasn't aware of the danger.......
WARNING: Shallow water blackout kills
Powered by CDNN - CYBER DIVER News Network
by DAVID WHITING
COSTA MESA, California(18 June 2008) — Free diver Gary Knap takes a series of big breaths, exhaling deeply each time.
Knap plans to try and swim 175 feet underwater in a pool without surfacing. Hyperventilating, many people believe, will allow a person to stay underwater longer.
He pushes off. By the middle of his third lap he notices things start to go black. But he feels OK and keeps swimming.
Seconds later, Knap is seen touching the wall. But his body slides to the bottom of the pool, unconscious. A friend swims down and saves him. Knap doesn't even remember finishing.
Fast forward several years. I'm snorkeling, free diving if you will, at Shaw's Cove in north Laguna Beach.
A sea lion stares at me, her brown eyes big enough to melt any human heart. She curves her body into a crescent, and with a flip she zooms off, leaving a trail of bubbles.
My lungs feel ready to burst. I head toward sky, breaking the surface gasping for air. I fill my lungs to join my new underwater friend, but before too long I have to head up again. I need oxygen, desperately.
Why could Knap swim far longer than I underwater? Why did he quietly slip into unconsciousness while my body's need for air literally forced me to the ocean's surface?
Part of it may be that Knap was in better shape. But the reasons likely have far more to do with the way our bodies function.
More importantly, the answers also may tell what happened on Saturday off Santa Catalina Island when a fit, certified scuba diver and strong swimmer died snorkeling, or free diving in 38 feet of water off his dad's boat.
Register writer Erika Ritchie reported Tim Hatch, 31, of Costa Mesa apparently died from something called shallow water blackout, "a loss of consciousness caused by cerebral hypoxia, or deprivation of oxygen to the brain."
Her report saddened me, and freaked me out. I'm a certified (elapsed) diver and have been snorkeling since I was 11. But I had no knowledge of this thing.
What causes shallow water blackout? Are we all at risk?
I talked to lifeguards, scuba instructors, researched online and interviewed Hatch's father, Bob.
His son was in terrific shape, Hatch told me on Monday. He recalled Tim riding his bike from Costa Mesa to Anaheim Hills for a family get-together, running 10 miles at a stretch twice a week, entering the O.C. Marathon in January, working out at the gym.
Father and son shared a true love of the sea, diving together nearly every weekend for years and visiting such scuba meccas as Cozumel, Aruba and St. Lucia. Hatch said he hoped others could learn from his son's death.
Tim Hatch and his fiancee, Michelle Oyler. Hatch died last weekend while diving at Catalina Island.
I discovered swimmers, surfers, divers, pretty much anyone hyperventilating while in water can drown from shallow water blackout.
It's worth taking a moment to understand:
1. Hyperventilating doesn't supersaturate your lungs or body with oxygen, as some believe. It can't. The body already is saturated with oxygen through normal breathing.
2. Hyperventilating does expel large amounts of carbon dioxide. This may sound good. But it's not. The urge to breathe, in fact, is triggered by high levels of carbon dioxide.
3. When you hyperventilate you can fool your body into thinking it doesn't need to breathe.
PADI, the international scuba diving certification organization based in Rancho Santa Margarita, puts it more bluntly in its textbook:
"Excessive hyperventilation – more than three or four breaths – can be dangerous because you can lower your carbon dioxide levels so far that your body runs out of oxygen before you get the urge to breathe.
"This can lead to sudden unconsciousness – without warning – and drowning. Don't hyperventilate excessively."
Knap knew about shallow water blackouts before he went into the pool that day. A friend of his had died from such a blackout.
But Knap, a chemical engineer who lives in San Clemente, wanted to find out more. He asked a buddy to swim over him while he conducted his experiment. Clearly, a risky move and something that no one should try.
"I always believed that you couldn't get into trouble free diving," Bob Hatch told me.
I had thought the same as Tim's father – until his son taught me a lesson.
WARNING: Shallow water blackout kills
Powered by CDNN - CYBER DIVER News Network
by DAVID WHITING
COSTA MESA, California(18 June 2008) — Free diver Gary Knap takes a series of big breaths, exhaling deeply each time.
Knap plans to try and swim 175 feet underwater in a pool without surfacing. Hyperventilating, many people believe, will allow a person to stay underwater longer.
He pushes off. By the middle of his third lap he notices things start to go black. But he feels OK and keeps swimming.
Seconds later, Knap is seen touching the wall. But his body slides to the bottom of the pool, unconscious. A friend swims down and saves him. Knap doesn't even remember finishing.
Fast forward several years. I'm snorkeling, free diving if you will, at Shaw's Cove in north Laguna Beach.
A sea lion stares at me, her brown eyes big enough to melt any human heart. She curves her body into a crescent, and with a flip she zooms off, leaving a trail of bubbles.
My lungs feel ready to burst. I head toward sky, breaking the surface gasping for air. I fill my lungs to join my new underwater friend, but before too long I have to head up again. I need oxygen, desperately.
Why could Knap swim far longer than I underwater? Why did he quietly slip into unconsciousness while my body's need for air literally forced me to the ocean's surface?
Part of it may be that Knap was in better shape. But the reasons likely have far more to do with the way our bodies function.
More importantly, the answers also may tell what happened on Saturday off Santa Catalina Island when a fit, certified scuba diver and strong swimmer died snorkeling, or free diving in 38 feet of water off his dad's boat.
Register writer Erika Ritchie reported Tim Hatch, 31, of Costa Mesa apparently died from something called shallow water blackout, "a loss of consciousness caused by cerebral hypoxia, or deprivation of oxygen to the brain."
Her report saddened me, and freaked me out. I'm a certified (elapsed) diver and have been snorkeling since I was 11. But I had no knowledge of this thing.
What causes shallow water blackout? Are we all at risk?
I talked to lifeguards, scuba instructors, researched online and interviewed Hatch's father, Bob.
His son was in terrific shape, Hatch told me on Monday. He recalled Tim riding his bike from Costa Mesa to Anaheim Hills for a family get-together, running 10 miles at a stretch twice a week, entering the O.C. Marathon in January, working out at the gym.
Father and son shared a true love of the sea, diving together nearly every weekend for years and visiting such scuba meccas as Cozumel, Aruba and St. Lucia. Hatch said he hoped others could learn from his son's death.
Tim Hatch and his fiancee, Michelle Oyler. Hatch died last weekend while diving at Catalina Island.
I discovered swimmers, surfers, divers, pretty much anyone hyperventilating while in water can drown from shallow water blackout.
It's worth taking a moment to understand:
1. Hyperventilating doesn't supersaturate your lungs or body with oxygen, as some believe. It can't. The body already is saturated with oxygen through normal breathing.
2. Hyperventilating does expel large amounts of carbon dioxide. This may sound good. But it's not. The urge to breathe, in fact, is triggered by high levels of carbon dioxide.
3. When you hyperventilate you can fool your body into thinking it doesn't need to breathe.
PADI, the international scuba diving certification organization based in Rancho Santa Margarita, puts it more bluntly in its textbook:
"Excessive hyperventilation – more than three or four breaths – can be dangerous because you can lower your carbon dioxide levels so far that your body runs out of oxygen before you get the urge to breathe.
"This can lead to sudden unconsciousness – without warning – and drowning. Don't hyperventilate excessively."
Knap knew about shallow water blackouts before he went into the pool that day. A friend of his had died from such a blackout.
But Knap, a chemical engineer who lives in San Clemente, wanted to find out more. He asked a buddy to swim over him while he conducted his experiment. Clearly, a risky move and something that no one should try.
"I always believed that you couldn't get into trouble free diving," Bob Hatch told me.
I had thought the same as Tim's father – until his son taught me a lesson.