Qns about DCS

[dive_lover88]

thanks all for clarifying my doubts !!

Hi seadoggirl, i would think that it would be interesting if someone releases the gas from the decompressing cylinders and left only 50 bar of gas for diver to decom and ascend.

 

[seadoggirl]

What if....

The vic gets a mix of too much o2 and gets trapped on fishing line during a wreck dive. O2 is easy because the killer works for a dive shop. Then on the dive she (Killer) is behind him (vic) and she snags his tank, then swims away. Waits until she knows that he is really low on air (at 120'), goes back to "save" him, so she doesn't look guilty. He shoots to the top. Dies on the boat, but it looks like she tried to save him to all the other witnesses on the boat. The tank is out of air, so nobody can test it. She also adds cumitin (blood thinner) to his food for a week prior to dive and in the attempt to 'free him' from the tangle she 'accidentally' cuts his arm. He is bleeding badly, bent, etc. Only other thing is to get him very drunk the night before and dive the Oriskany which is an hour overshore on the fastest boat. Believable?

 

[victor]

A but what if
The problem here is for the perpretrator to guarantee that it will be a fatal incident, this can be very hard as victims sometime do the most unusual things to survive.
If the diver is experienced then the perp will have to insure that they won't just take their BCD off, remove the tank, and just swim to the surface breathing off the first stage, e.g. they must be unconsious or equivalent.

I might propose a very low O2 mix, say 5% plus high CO2 and a reg that can be made to freeflow to empty the tank.
With the right weighting and a wall dive so the unconsious diver sinks down into the deep, tank empties and they pop back to the surface.

 

[seadoggirl]

How can I get the CO2 into the tank? I like the extra weight idea. The body sinks down the wall and something big and toothy eats his sorry #$%!

I'm already getting PMs from my friends. No I have not gone off the deep end. You guys relax, I'm to hard up for dive buddies it's none of ya'll. It's just a fictional fantasy.

 

[seadoggirl]

Sorry about stealing this thread. If you monitor guys want to kick me to another less serious place, you can. I just thought this would be a good place to get REAL ideas. Thanks all you doctor types, you guys put a good morbid spin on reality.

 

[Web Monkey]

thanks all for clarifying my doubts !!

Hi seadoggirl, i would think that it would be interesting if someone releases the gas from the decompressing cylinders and left only 50 bar of gas for diver to decom and ascend.

Already been done. It was on SeaHunt.

Terry

 

[seadoggirl]

Terry what about the rest....

 

[pupdiver]

Hello seadoggirl:

Death by DCS :shakehead

Frankly, mild forms of DCS (“the bends”) are not fatal. Additionally, they have a variable response for each “dose” of dissolved nitrogen. Death can really only result from a massive production of internal gas bubbles such that one gets either arterial gas bubbles or a blockage of the heart when it fills with foam.

[1] Recreational divers would not find normally themselves in such a situation. In “The Last Dive,” the two divers were very deep on air, became trapped/lost in a wreck, and surfaced without adequate decompression. They died. If you could “trap” your deep-diving victim in some manner and then cause him to ascend without possibility of adequate decompression, he would be in a serious amount of hurt.

[2] A diver needing to decompress with extra cylinders suspended in the water at depth would likewise be in trouble if the cylinders “mysteriously” were missing when he began the ascent to his deep deco stops.

[3] Most divers die by drowning, but this is boring in a novel. Closed circuit rebreathers have their fair share of fatalities. Arranging for a failure of the oxygen sensor would prove to be devastating.

[4] Carbon monoxide occasionally enters the compressed gas mix and often with fatal results. As long as the victim was not breathing the same gas as all the others on the boat, this is a possible scenario.

Dr Deco :doctor:

I vote for Option 2.

In Option 1, if you were to trap your diver and force him way into unplanned deco to kill him it would be inefficient. If you can trap him then you might as well trap him long enough to have him run out of air and drown. That just isn't that interesting.

In Option 3, I agree that just drowning is boring in a novel. The close circuit rebreather idea is too complicated. The average person doesn't know anything about rebreathers and how they work so it would require explanation. And, in the end, it is really just drowning anyway.

I like Option 4 better than the drowning options, but it would depend entirely on the way it is written. The only downside I see is that if you are strictly rigorous with it the diver probably wouldn't see it coming and you are back to him just drowning. Or, if he does realize something is wrong, realistically, he would probably surface.

I think you have a lot of choices with Option 2, plus you have better drama. If the diver knows he is doomed but can't do anything about it, you have something you can work with. He knows he is way into deco and his cylinders are gone. Panic is good drama. He has some gas left in his tank so he can think about what has happened to him, who may have done it, and what he can try to do to save himself.

Yup, Option 2 is the way to go.

 

[rawls]

Say the diver used a penetration line to go deep into a wreck to find a hidden treasure. It was a dive requiring deco stops. The villan cuts the penetratiion line after the diver has had a chance to get deep inside the wreck. Then like Dr Deco said, the villan takes the deco cylinders.

 

[Jim Lapenta]

This thread got real scary! But there are toxins that are easily administered and virtually undetectble unless specifically looked for. They could be administered orally, injected but this leaves a puncture wound that could be detected, placed in or on a reg(is the vic allergic to anything-peanut oil on a mouthpiece), and there are also contact poisons that are absorbed through the skin(sprayed inside a suit perhaps). What about naturally occurring substances? Hawaii Five-O did a show where the killer used conshells that he kept in an aquarium to kill his vics. Do a search on poison's and I'm sure you will find a lot of info especially if you look for exotic ones.