what the different between using Nitrox and Normal Air to dive???

[Rich Keller]

"However, you increase your exposure to oxygen. Oxygen is toxic at high levels and can cause convulsions (something to be avoided whilst scuba diving). So you have to watch your oxygen levels and your nitrogen levels whilst diving. Functionally, this is not a big factor if you do not push the depth limits whilst diving on nitrox."

"Some poeple claim that diving on nitrox makes them feel much better than they would after diving on air."

The increased risk in using Nitrox comes from oxygen poisoning. Every body is different as far as their body reacts so an oxygen tolerance test is needed to see if this will cause you problems. Does anyone have students take that test before going into a Nitrox class? As far as feeling better after a dive on Nitrox that is due to the oxygen level. Try pure oxygen for a hangover and you will see what I mean.

 

[PfcAJ]

Oxygen tolerance tests aren't really reliable. There is enormous within subjects and between subjects variation.

Just because you don't tox under one condition one time doesn't mean you won't tox under the same condition some other time. Its far more complicated than that.

 

[Cave Diver]

Oxygen tolerance tests aren't really reliable. There is enormous within subjects and between subjects variation.

Just because you don't tox under one condition one time doesn't mean you won't tox under the same condition some other time. Its far more complicated than that.

Not to mention the fact that using nitrox at recreational limits within the recommended maximum operating depths the chances of tox is very slim.

 

[Ana]

Nitrox was invented by NOAA for use at shallow water decompression stops not for diving at depth. The Navy Experimental Diving Unit said the increased risks of using Nitrox at depth far out weigh any benefits. For that reason I have never gotten involved in Nitrox but in all the posts in reference to using it I have never heard anyone talk about taking an oxygen tolerance test first. This test is standard operating procedure in commercial diving though for different reasons. Do the people teaching Nitrox have anyone take that test?

I'm curious to know when and under what context did NEDU stated that the risks of Nitrox out weight its benefits, because the Navy has procedures for using it in their Dive manual.

 

[PfcAJ]

Sounds like the old "voodoo" gas arguments of yore.

Recreational diver's aren't exactly dropping like flies using nitrox...

 

[boulderjohn]

Oxygen toxicity has been studied pretty thoroughly, and the limits put on recreational divers for maximum depth and time are extremely conservative and thus very safe. What was once thought to be be so dangerous that PADI would not allow it is now considered so safe that PADI allows it to be used by OW students on their 4th certification dive.

 

[BrianKon]

The 2 biggest benefits for using Nitrox are

1. for those divers susceptible to DCS, you can dive Nitrox and use an Air computer as long as you do not exceed maximum depth limits for the %Oxygen. which are much shallower, 32% EANx is 110 feet. The air computer offers an extra safety factor, dive as if on Air and you will be well within oxygen and nitrogen safety factors. CAUTION: this is for 1 or 2 tank dives, extended diving requires a Nitrox Computer as you cannot exceed 100% O2 in any given day, more on this when you GET CERTIFIED - A MUST to dive Nitrox.

2. to extend bottom times for deeper than average diving, you can stay down longer at 100' using 32% EANx than on Air- almost double - this is good for wreck diving, however I would take both a Deep Diver Specialty Course as well as the REQUIRED EANx(Nitrox) course. before doing such diving.

hope this helps.

You can try Nitrox via a PADI Instructor in the Dive Today program, it wont be a deep dive , but you can at least try it first.

Discover Nitrox is also offered- with this cert, you must dive with professional supervision. This course can be credited towards your Specialty.

hope this helps.

Brian

 

[Rich Keller]

"NITROX breathing gas mixtures are normally used for shallow dives. The most benefit is gained when NITROX is used shallower than 50 fsw, but it can be advantageous when used to a depth of 140 fsw.

Advantages and Disadvantages of NITROX Diving.

The advantages of using NITROX rather than air for diving include:
Extended bottom times for no-decompression diving.
Reduced decompression time.
Reduced residual nitrogen in the body after a dive.
Reduced possibility of decompression sickness.
Reduced Nitrogen Narcosis

The disadvantages of using NITROX include:
Increased risk of CNS oxygen toxicity.
Producing NITROX mixtures requires special equipment.
NITROX equipment requires special cleaning techniques.
Long-duration NITROX dives can result in pulmonary oxygen toxicity.
Working with NITROX systems requires special training.
NITROX is expensive to purchase."

The above quote is from the US Navy Diving Manuel. I will try to attach a copy but it is a big file so it may not work.

To be clear they did NOT tell me it could not be used at depth just that the increased risk far out weighed the benefits. Which brings me back to my original question. Is anyone giving oxygen tolerance tests to people before they take a Nitrox class?

PS: The file did not seem to attach. I can email a copy to anyone who would like one.

 

[Cave Diver]

The disadvantages of using NITROX include:
Increased risk of CNS oxygen toxicity.
Producing NITROX mixtures requires special equipment.
NITROX equipment requires special cleaning techniques.
Long-duration NITROX dives can result in pulmonary oxygen toxicity.
Working with NITROX systems requires special training.
NITROX is expensive to purchase."

The above quote is from the US Navy Diving Manuel. I will try to attach a copy but it is a big file so it may not work.

To be clear they did NOT tell me it could not be used at depth just that the increased risk far out weighed the benefits. Which brings me back to my original question. Is anyone giving oxygen tolerance tests to people before they take a Nitrox class?

Most of those disadvantages listed apply more to Nitrox blends above 50%. Not really applicable to recreational divers use.

 

[Rich Keller]

"Nitrogen-oxygen (NITROX) diving is a unique type of diving using nitrogen- oxygen breathing gas mixtures ranging from 75 percent nitrogen/25 percent oxygen to 60 percent nitrogen/40 percent oxygen."

Again the above is a quote from the US Navy Diving Manual.

The range they are talking about is 25% to 40%.