50% Nitrox for deco-unsafe?

[RJB2014]

I was dropping off my tanks to get re-filled after a dive this weekend when some guy started asking me a bunch of questions about the gases I was using. Initially I though he was just being curious. I told him I was using 50% for accelerated deco starting at 60 feet (which is well below ppO2 1.6). He then started telling me how he was a Navy master diver for 30 years and that using 50% below 50 feet was foolish because it raises the risk of Oxtox with little benefit in offgassing. He was bit of an aggressive jerk so my initial reaction was to ignore him since everything I've been taught and read (TDI, GUE, PADI) generally supports O2 mixes up to pp1.6 for nonactive, deco portion of dives (again, I was well below this on my profile anyway). I normally don't put a lot of stock in know-it-alls who spout out unsolicited information that goes against the recommendations of well established training organizations. However, on the other hand I don't want to be pig-headed and potentially ignore good advice. Can anyone comment on the validity of his assertion that the increased risk of using 50% below 50 feet isn't justified by the benefit of increased offgassing?

 

[Brandon]

Can anyone comment on the validity of his assertion that the increased risk of using 50% below 50 feet isn't justified by the benefit of increased offgassing?

I normally don't put a lot of stock in know-it-alls who spout out unsolicited information that goes against the recommendations of well established training organizations.

Go with your gut instinct on this one - you answered your own question =)

 

[PfcAJ]

First class baloney. Carry on as you have been.

 

[p1p]

He's overflowing with that smelly toilet stuff.

 

[Locus]

Sounds like he did a lot of diving back when hyperoxic mixes were used solely by militaries and government agencies. Maybe he's still scandalized at the thought of sport divers using nitrox.

 

[Wookie]

I've had navy divers tell me "the reason you're bent" is from doing more than 2 dives per day, and also stand and accuse me of putting divers in danger because I offered more than 2 dives per day as a charter operator.

But cut those old fossils some slack. You've seen Men of Honor. Navy divers were taught a certain way to do a certain thing that has nothing to do with what we do, and they consider what they did safe, and what we do foolish. It's all in what you were taught and how flexible your mind is. I assure you that without those guys experimenting and getting hurt for us, we wouldn't be diving like we do today. Thank him for his service and advice and move along. Nothing to gain there.

 

[jadairiii]

....He then started telling me how he was a Navy master diver for 30 years ....

First clue he was FOS. Surprised he did not tell you he was a Navy SEAL also.

 

[FinnMom]

A good example of "My mind is made up" (30 yrs ago apparently) "and I'm not going to have you trying to confuse me with the facts".

 

[decompression]

Wow, ignore and carry on.


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[Capt Jim Wyatt]

This ex-US Navy Diving/Salvage officer tells you that the other navy diver is full of crap.

EAN50 @ 70 feet is appropriate, then switch to 100% at 20 feet.