RMV Spinoff from Accident & Incident Discussion - Northernone - aka Cameron Donaldson

[markmud]

...but trying to short circuit the whole "process" and just trying to use less air and viewing it as a surrogate for diving skills is very shortsighted and probably dangerous.

Hi johndiver999,

May I add that no human being can overcome the laws of physics and the laws of chemistry.

For every action there is an equal but opposite reaction. For this discussion, it may not be in direct proportion or linear, but something will change with your physiology. A chemical imbalance will occur. Your body will react and cause more side effects.

As @rsingler has written add nauseum: to what end (paraphrased)? Bragging rights? Or, the Russian roulette hammer coming down on a live primer and charged cartridge?

Thanks to those who posted on this thread. Especially, @rsingler and @Compressor. It has been educational.

markm

 

[markmud]

@rsingler and @Compressor,

I have a scenario that I would like to run by the two of you.

A diver is in decent physical condition. He/she exercises (cross trains) but is not at an athletes level of condition. This diver has an above average vital capacity, tidal volume, and etc. Good cardiovascular numbers.

This diver practices abnormal breathing techniques to decrease his/her SAC/RMV for scuba diving. Their bodies have acclimated somewhat to the side effects of higher than normal blood CO2 levels.

Now, life gets in the way. They are busy at work, a new baby, a sick relative and/or etc.

They stop cross training. Their physical condition decreases as they have become sedentary.

If this diver jumped in the water and tried to dive as they did when they were at their peak (acclimated to high CO2) and tried to dive with a low SAC/RMV, would the effects of high CO2 be more pronounced? In other words, they are using abnormal breathing techniques to "sip" gas as they had when they were physically fit.

thanks,
markm

 

[rsingler]

@rsingler and @Compressor,
If this diver jumped in the water and tried to dive as they did when they were at their peak (acclimated to high CO2) and tried to dive with a low SAC/RMV, would the effects of high CO2 be more pronounced?

With the caveat that this is pure conjecture, I'd say, "A little of both." I think when the hypothetical diver got back to it, his headaches might be temporarily worse, but his susceptibility to a CO2 hit wouldn't be, but only because when he was fit, that hadn't conferred any resistance to CO2 toxicity. He was as close to the edge when he was skip breathing with abandon, as he is now that the practice makes him feel "off."
You can't train out of susceptibility to a CO2 hit, even if skip breathing doesn't gives you as bad a headache any more. Two different mechanisms. Headache is vasodilation/vasoconstriction-related, akin to a migraine. The narcotic effect is central in your brain.

 

[Storker]

Headache is vasodilation/vasoconstriction-related, akin to a migraine.

And for some of us, it's associated with having to bend our neck backwards, which we have to do if we're in horizontal trim and want to look forward. Unlike how it is topside, when we're standing upright.

Basically, slightly overworked neck muscles. Not uncommon for desk jockeys.

 

[rsingler]

if we're in horizontal trim and want to look forward.

Simple solution, @Storker !
Just dive out of trim!

 

[markmud]

And for some of us, it's associated with having to bend our neck backwards, which we have to do if we're in horizontal trim and want to look forward. Unlike how it is topside, when we're standing upright.

Basically, slightly overworked neck muscles. Not uncommon for desk jockeys.

Hoo-aa ouch. I know that feeling.

m

 

[RayfromTX]

Cameron Donaldson (northernone) a requiem

 

[John C. Ratliff]

Not a correct assumption. There are currents that can defeat the best of scooters, let alone a swiming diver, and they do with you what they will, be it up, down, or sideways, and all during the same 'experience' sometimes. You may have no say in the matter. A recreational dive of such an example familiar to me is off Roca Redonda in the Galapagos Isl. with a self explanitory name called 'The Washing Machine'. Another in Palau. Another in the Solomons. Actually, there are many places notorious for them. Caveat (or in this case, diver ) Emptor.

I am an older diver, but want to comment on the use of scooters by tech divers. From my perspective, tech divers are using scooters to overcome their equipment encumbrance and lack of streamlining. By using scooters, they can be nearly as efficient in the water as if they were diving “slick” as we did in the ol’ days. The currents will play with that lack of streamlining, and the resistance to forward movement even with a scooter.

SeaRah

 

[boulderjohn]

I am an older diver, but want to comment on the use of scooters by tech divers. From my perspective, tech divers are using scooters to overcome their equipment encumbrance and lack of streamlining.

Sure.

Oh--was that a criticism?

If you have a lot of gear to carry, scooter is a big help.

 

[John C. Ratliff]

Sure.

Oh--was that a criticism?

If you have a lot of gear to carry, scooter is a big help.

This is not a criticism, but an observation. I have been studying underwater swimming efficiency for decades, and at one point was the Finswimming Director for the Underwater Society of America. The scooter helps overcome the lack of swimming efficiency I see in the tech community. However, the down-side of this is that if the scooter decides to not work, then the diver has to still move through the water, but this time by him/herself.

SeaRat