Virginian diver dead at 190 feet - Roaring River State Park, Missouri

[Manatee Diver]

What methodology or reasoning is behind using TMx30/30 as a preferred Trimix blend for any depth?

OC Florida Cave diving, you can often be working hard at 100ft so having a bit less PPN2 and gas density for to help ease narcosis. Before I got dedicated trimix tanks I could notice the difference on the following dives. That being said I don't know anyone rich enough to use it OC and I believe @kensuf mentioned that in his opinion the PPO2 is too high for dil in CCR. But that might be a difference due to High Springs DIR style SOP.

 

[DOBY]

Thanks. Never heard that before.

During all my trainings and 20 years of diving Florida cave county never saw or heard of TMx30/30 as dil. Most shops I use bank EAN32 or EAN30 (as some say EAN32 is a bit high for the deeper 110 foot depths like L. River) for OC. And air for on board dil or the OC EAN32 bailout as off board dil for CCR.

I agree with Ken, the pO2 of EAN 32 might be a little high as dil anything below 100ft (JMHO).

 

[Tracy]

??? Can someone please explain why TMx30/30 would be a “preferred mix” for anything? For example, it has a 100ft MOD at a pO2 of 1.2ata. So why even the need for 30% He, as the maximum pN2ata (2.8ata) would already be below the 3.2 pN2ata of air at 100ft before adding Helium. Seems like a totally useless gas mix.

I was taught to set your pO2 to 1.0ata at depth. Then set the pN2 to 3.2ata at depth (pN2ata of air at 100 feet). And lastly make the remaining Helium.

For example: 200ft FW. (200ft/33ft)+1ata = 7.1ata total.

(1.0 pO2ata / 7.1ata total) * 100 = 14% O2
(3.2 N2ata / 7.1ata total) * 100 = 45% N2
100% - 14% O2 - 45% N2 = 40% He

Gives you TMx14/40.

What methodology, reasoning, or calculation is behind using TMx30/30 as a preferred Trimix blend for any depth?

It lessons the WOB as a diluent. Much nicer dil for swimming Ginnie than 32. Both work, 30/30 is easier to breathe.

 

[tursiops]

At least 3 factors may have contributed to diver's death at Missouri spring, report finds

Investigative reports obtained by the News-Leader detail the Missouri State Highway Patrol's findings in the October drowning death of Eric Hahn.

www.news-leader.com

 

[lostsheep]

Wow

 

[PEDiver]

Another tragic story of a diver dying due to a mix issue. 190 feet using 26% and with no helium. 1.8 ppo2 recorded on the computer. Do we know if he had a HUD?

 

[lostsheep]

I would like to know what was in his right side cylinder

 

[Manatee Diver]

I would like to see the actual documents released. Obviously if it is published in a newspaper then any concerns about privacy are out the window.

 

[Robert H. Diver]

Wow

 

[Tracy]

Another tragic story of a diver dying due to a mix issue. 190 feet using 26% and with no helium. 1.8 ppo2 recorded on the computer. Do we know if he had a HUD?

I don't get planning a working dive at 190' with no helium. If this article is factual, and I don't know if it is. The guy was just playing Russian roulette and lost.