Nitrox safer than air

[Uncle Pug]

Northeastwrecks once bubbled...
(thereby avoiding any of the problems I've heard about boats not accepting GUE cards).

As for the sub, we would welcome the opportunity to have you out. You could ship your tanks out via carrier.

That's nuts... really?? Gotta be an urban myth.

Anyway one of these days I am going to become a travelling diver... I do want to get to the Great Lakes, the East Coast, Florida and Mexico.... (maybe even Oz) and shipping the stuff sounds like the way to go unless we get serious and put it all in a trailer and do an overland trip! Yes... put a Honda on the RIX and pump our own too.

 

[Stone]

Although "Safety Factor" may be accepted terminology, it is, in reality, a "conversion factor" and does not give an accurate indication of the "Safety Margin" that can be obtained by diving Nitrox on an air table.

I make this distinction because Scuba originally asked:

Does it reduce the risk of DCS by 1 % or 70 %, for example.

and I was looking for a way to answer his question.

 

[Uncle Pug]

Stone once bubbled...
Although "Safety Factor" may be accepted terminology, it is, in reality, a "conversion factor"

You are absolutely right...
I will immeadiately amend my vocabulary...
or try to...

 

[MikeFerrara]

I use nitrox with air tables to provide a "safety margin". On teaching weekends I sometimes have a pretty aggressive schedule. I agree in principal with standardized mixes. In practice, though I sometimes deviate from my standard mixes. I am content to use ean32 as you don't need more for shallow dives and it gives more head room on the deep side than say 36% or 40%. However on heavy teaching days I may start out the day with a 100+ ft, followed by a 80+ ft, followed by an afternoon that includes two 40 ft dives and doing esa's with 5 or six students (which could mean more than 5 or 6 esa's). In a case like this I will use ean50 to deco from the 100+. I will again use the 50% for the ascent from the 80 ft. I will use 32% or 36% for the shallow stuff with all the ups and downs. There is no chance of mixing up the EAN50 and the EAN32 because the tanks dont look anything alike. The EAN50 bottle has stage rigging and is a dedicated bottle with BIG MOD markings and none of the other typical EANX type markings (I am the only one who fills it). Does it help? I don't know but I haven't been bent. Some instructors do the same thing on air.

 

[Northeastwrecks]

Uncle Pug once bubbled...

That's nuts... really?? Gotta be an urban myth.

It might be, but that's what I've heard.

FWIW, none of the boats I use regularly would pull this. As it stands, they want to know our general dive plan and when we will be back up. We tell them if we're planning S-drills that include shooting a bag so that they won't worry. Other than that, we're on our own.

I have heard (not just on this Board) that some of the boats, particularly Long Island and Jersey boats, want to see a TDI or IANTD card before they let you run a deco profile or dive mix. I want to expand my diving to include Jersey and Long Island dives, so this concerns me.

The easiest solution is to get the cards, even if this is just a rumor. Besides, I'll take whatever training I can get. Taking DIR-F and Tech 1 doesn't mean that I won't learn valuable information from TDI Adv. Nitrox and Deco Theory. Indeed, having those theories pounded into my head more than once is probably a good thing. Even better, the TDI instructor encourages a DIR configuration, so they should complement each other.

Finally, I've heard that the GUE courses are a cast iron B!!!!. I'd rather concentrate on the skills portion while having a leg up on the gas theory side.

 

[MikeFerrara]

I think it's true. There has been alot of stuff on a number of lists including this one, I think. I also think someone posted a response they recieved from one of the charter captains. This is from memory so don't quote me but I believe it was from the captain or owner of the Seeker. He said it was due to insurance or not being a recognized agency or something like that. I think it's because GI has bad mouthed them guys so much. Anyone can start their own agency. Everyone can choose wether of not they recognize it.

 

[Scuba]

I found a good article on Nitrox here:

http://www.scubadiving.com/gear/truthnitrox/

 

[Dr Deco]

Dear Readers:

Safety factor

The short answer is that if you use nitrox on air tables there is a safety factor conferred.
This is because you have reduced your dose of nitrogen. If one were to calculate the load, you would see that you are diving shallower with respect to the amount of dissolved nitrogen in the tissues.

If, on the other hand, you dive on nitrox tables to their limits, you remove the advantage of safety because you have traded reduced nitrogen for extended bottom time.

The exact "safety factor" could be calculated from the "maximum likelihood" method, but the numbers found do not usually correspond the recreational diver experience.

Safe anyway

The reported incidence of DCS is so low with dive tables that the difference almost vanishes anyway.

It is my person believe, that more divers will experience problems if they are dehydrated, are too sedentary in the surface intervals (= poor off gassing), engage in weight-intensive activities on the surface (lifting, hauling, jumping, etc = micronuclei buildup).:boom:

Dr Deco :doctor:

 

[padiscubapro]

Northeastwrecks once bubbled...

It might be, but that's what I've heard.

FWIW, none of the boats I use regularly would pull this. As it stands, they want to know our general dive plan and when we will be back up. We tell them if we're planning S-drills that include shooting a bag so that they won't worry. Other than that, we're on our own.

I have heard (not just on this Board) that some of the boats, particularly Long Island and Jersey boats, want to see a TDI or IANTD card before they let you run a deco profile or dive mix. I want to expand my diving to include Jersey and Long Island dives, so this concerns me.

The easiest solution is to get the cards, even if this is just a rumor. Besides, I'll take whatever training I can get. Taking DIR-F and Tech 1 doesn't mean that I won't learn valuable information from TDI Adv. Nitrox and Deco Theory. Indeed, having those theories pounded into my head more than once is probably a good thing. Even better, the TDI instructor encourages a DIR configuration, so they should complement each other.

Finally, I've heard that the GUE courses are a cast iron B!!!!. I'd rather concentrate on the skills portion while having a leg up on the gas theory side.

I can give you info on some of the LI boats.. Most importantly, If they don't know you, you need to bring your log book.. No log no dive(unless a regular who is also an instructor is willing to take responsibity for you)..
The wahoo has crew members who are DIR so that boat shouldn't be a problem.. The 2 boats I use most often Wreck Valley and Eagles Nest, allow deco profiles, and only allow Solo diving to certain divers. Most of the other boats are pretty much the same, be equipped properly, have a buddy and bring your logs, If its planned for more than 1 dive site stay within the time constraints.
On A particular day I had to take responsibility for another instructor who was never on the Eagle's Nest and failed to bring a log book.. Howard doesn't care what card you hold, its experience that counts.. (on certain dives he does require the diver me mixed gas certified).