Wrong gases?

[chris1511tay]

Breaking News

 

[I Dive]

"The tank, which should have contained 80 per cent oxygen and 90 per cent nitrogen"

I'm not even going to comment on that absurd statement...

 

[Scared Silly]

When I see such crappy reporting I write letters such as this to the editors.

Dear Sir,

I just read this article:

http://www.straitstimes.com/Breaking+News/Singapore/Story/STIStory_299516.html

The reporter noted "The tank, which should have contained 80 per cent oxygen and 90 per cent nitrogen, was found instead to have 785 parts per million (ppm) of carbon monoxide and 12.3 ppr of hydrogen sulphide. "

There several problems with this statement, first is that it incorrectly joins two unrelated facts. What should have been written "The tank, which should have contained only trace amounts of carbon dioxide and hydrogen sulphide, was found instead to have 785 parts per million (ppm) of carbon dioxide and 12.3 ppr of hydrogen sulphide. Further, it was given with no context, i.e. what level of carbon monoxide is consider to be lethal. For the reporters edification, carbon monoxide becomes toxic when it reaches a level higher than 50 ppm. I will not even begin discuss the affect of breathing carbon monoxide at depth (i.e. under water) which compounds the problem.

Next, I am not sure what math the reporter learned but it is obvious they failed miserably. "80 per cent oxygen and 90 per cent nitrogen" That totals 170 percent. Last time I checked the sum of parts had to equal 100 percent. Further, air normally contains 21% oxygen and 79% nitrogen. Most 5th graders know that basic science fact.

Please educate this reporter.

Sincerely,

SS


Now the only acceptable mistake is the 35m versus 35 feet. Given it was an open water course I do not think they would be at 35m.

Finally, sad to see such an accident as it is totally preventable. Condolences to the man and his family.

 

[freediver]

"The tank, which should have contained 80 per cent oxygen and 90 per cent nitrogen"

I'm not even going to comment on that absurd statement...

hehe, kinda like Yogi Berra saying "90% of the game is half mental".

 

[Scared Silly]

hehe, kinda like Yogi Berra saying "90% of the game is half mental".

Actually it is not. What Berra said is reasonable. What the reporter wrote is not.

 

[nadwidny]

Next, I am not sure what math the reporter learned but it is obvious they failed miserably. "80 per cent oxygen and 90 per cent nitrogen" That totals 170 percent. Last time I checked the sum of parts had to equal 100 percent.

I'm just glad the reporter went into journalism and not engineering.

 

[wilde100]

The online report omits information available from the print edition.
Being that Mr Sue's tank was the only tank that tested positive for this result. There were 24 other tanks on the boat. Tests (not sure if all or just sample tanks) showed an acceptable measurement. Operator stated he filled tanks by the book (unverified).

Truely unfortunate that an open water student picked the tainted tank. What are the chances?? Had it been a more experienced diver / instructor I doubt the outcome would have been this bad. Afterall Mr. Sue did surface. Had he inflated his BC and kept calm, I believe he would have been rescued.

Also, not unlikely that as an open water student (with untrained bouyancy control) he could have been overweighted. Combined with exhaustion from fighting a strong surface current and deflated BCD, he may have drowned from over exhaustion.

Unfortunate really. But I am very curious on what his instructor did besides notifying the boat crew.

 

[ronbeau]

"The tank, which should have contained 80 per cent oxygen and 90 per cent nitrogen"

I'm not even going to comment on that absurd statement...

Obviously the reporter failed his/her basic math courses. It is even worse if the reporter had the story reviewed by an editor who also failed basic math.

 

[broadreach]

Obviously the reporter failed his/her basic math courses. It is even worse if the reporter had the story reviewed by an editor who also failed basic math.

Makes you wonder about Singapore's venerated math education....

Now the only acceptable mistake is the 35m versus 35 feet. Given it was an open water course I do not think they would be at 35m.

Since this is metric Singapore I highly doubt that they confused feet with meters.
Dolphin state on their website that the site is 15m deep. Maybe someone more familiar with Pulau Hantu could comment about the site in further detail. I have never dived there, but remember hearing from local operators in S'pore that normal conditions involve poor viz and strong currents.

 

[DandyDon]

I wonder if the story got confused in translation, not originally written in English?

The online report omits information available from the print edition.
Being that Mr Sue's tank was the only tank that tested positive for this result. There were 24 other tanks on the boat. Tests (not sure if all or just sample tanks) showed an acceptable measurement. Operator stated he filled tanks by the book (unverified).

It's not unknown at all for one tank from a batch having higher CO ratios than the rest as a running compressor can certainly change as it gets hot and/or a contamination source can be moved close to the intake, altho that is a very high level. My bud and I test every tank before diving them, not just some.

The description for the effect of 785 ppm CO is verbatim from many recognized descriptions and it's not surprising that a reporter would have no knowledge of the increased effect at depth. Sloppy, but typical.

Truely unfortunate that an open water student picked the tainted tank. What are the chances?? Had it been a more experienced diver / instructor I doubt the outcome would have been this bad. Afterall Mr. Sue did surface. Had he inflated his BC and kept calm, I believe he would have been rescued.

Also, not unlikely that as an open water student (with untrained bouyancy control) he could have been overweighted. Combined with exhaustion from fighting a strong surface current and deflated BCD, he may have drowned from over exhaustion.

Unfortunate really. But I am very curious on what his instructor did besides notifying the boat crew.

I don't know that a certified diver would have fared better necessarily, other than maybe the rotten egg smell may have stopped one from diving the tank. 785 ppm is an alarmingly high CO rate, but we've seen reports of divers with tanks almost that high who descended, became ill faster from the effect of depth, then violently ill on ascent, subsequent dying. We do not know how many CO deaths are written off as drownings without tests after scuba deaths.

And we've seen many reports of certified divers surfacing in trouble, failing to ditch weights, and drowning.

I have to wonder if this part could be accurate and true, that Sue waved?

A lifebuoy attached to a rope was thrown to him but it was too short. Mr Sue was last seen waving his hands before sinking in the water with strong currents pushing the divers away from the boat.

That Sue was a student made him somewhat more vulnerable as a student is certainly diving all trust-me dives, but very few divers currently test their tanks for CO, inspect compressors or anything else to prevent CO poisoning.