Pros and cons of Nitrox

Discussion in 'New Divers and Those Considering Diving' started by Robertobowhunter, Apr 9, 2012.

  1. Robertobowhunter

    Robertobowhunter Angel Fish

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    Location: Quito-Ecuador
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    Hi,

    I´m a total newbie (just had our 12th inmersion with my wife) and I´ve seen lots of divers with Nitrox, all of them says "yeah man you should go nitrox, you´ll have more fun".

    They all says that by going nitrox I´ll be able to do more tanks in one day (depending on how deep and the BT) and will feel less tired at the end of the day.

    The Nitrox sounds good to me since we are going to the Galapagos in 3 weeks and Bonaire in July.

    Would you please give me any word of advice on Nitrox?


    Thanks and regards
    Robert J
     
  2. LiveBait

    LiveBait Nassau Grouper

    # of Dives: 100 - 199
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    In my opinion it really is a no brainer cert. You could even do it online. I chose to take mine with my AOW. There are lots of pros. to having it and, I have only one con. That is that I can get practically free air fills at 5$ but, to get a nitox fill its 15! So I generally use air when I dive in the local shallow quarry (35'). Even if that is the case in your area I would still get it.

    Also if you plan to get lots of other training...it is a good get to know you course, to see if you like that instructor and how they teach.
     
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  3. jar546

    jar546 Scuba Instructor

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    More bottom time, less surface interval = more diving

    Just watch your MOD which should be preplanned anyway.

    Yes, I agree, a no-brainer cert
     
  4. TMHeimer

    TMHeimer Divemaster

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    I use it sparingly. As pointed out, depth and number of repetitive dives plays a big part. Yes, it can be much more expensive than air. Again, depends--If you're already spending a fortune on a charter trip the extra bottom time is most likely worth it. It is convenient to dive nitrox if your buddy or everyone is, or air if the others are--so same bottom times. Consider however your standard US 2 tank charter with a good surface interval and a crew on a schedule -- requiring time limits on the dives--may or may not be worth double or tripple the cost of air. "Feeling better"? I never noticed a thing.
     
  5. RTee

    RTee Divemaster

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  6. rhwestfall

    rhwestfall Surface Interval Member

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    Is your current diving limited by air in your tank, or your NDL? If the latter, it will be a benefit. If not, until that happens, there is little benefit. If you are NDL limited, it will be a great advantage on multiple dive days (like three or more). Bottom time and SI's can be significantly altered.
     
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  7. boulderjohn

    boulderjohn Administrator Staff Member

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    When I went to the Galapagos, we had the option of both nitrox and larger tanks to get more bottom time. Everyone on the boat opted for both except for one couple. I could not understand it. They had to surface well before everyone else on every dive. They saved a couple hundred dollars all told, but if you are spending thousands of dollars for the trip, that was a relative pittance. If you are going to do such a trip at such an expense, spend a few more bucks and get the most out of it.

    On the other hand...

    You should be aware as a new diver that the Galapagos is not easy diving. You may find your skills quite challenged there.
     
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  8. t-mac

    t-mac Barracuda

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    Location: VA, USA
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    Agree it's a no-brainer. You WILL want it eventually and I predict you will want it in the Galapagos. Don't wait to get there to discover this. I don't know what you are paying for your trip, but the cost of the course and the extra couple of bucks per tank (assuming they charge for it), are likely to be inconsequential. And I assume this is a once-in-a-lifetime trip; it would really suck not to see that school of hammerheads because you had to sit out that dive. The only real downside is you have to watch your depth, but you can adjust your nitrox blend to the expected depth of your dive. Worst case is if your NDLs are not pushed by air and you don't "need" the nitrox, you have added a safety margin -- less nitrogen loading, less DCS risk. No brainer for sure!
     
  9. Dive Bug Bit Me

    Dive Bug Bit Me Barracuda

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    Hi Robert, and welcome to the world of scuba.

    I firmly believe that nitrox is the one speciality that is beneficial for every diver. My wife completed Nitrox (Enriched Air Speciality) when she had 12 dives, so you don't need to wait for more experience. . . just do it.

    Nitrox is just a term used to describe a breathing mix with Nitrogen and Oxygen. Technically air is Nitrox with 21% oxygen. Usually recreational nitrox refers to breathing gasses with more than 21% oxygen and less than 40% oxygen. Practically 32% seems to have become common and is often offered in places like Bonaire.

    In terms of the benefits;
    1. You will find that the no deco limits are extended. This allows for more bottom time, either as a single long dive, or spread over a number of dives over a day or week. This is the primary benefit that divers would think about - more diving.
    2. Some claim that they feel more invigorated after diving on nitrox. There is a mixed view on this and there is no scientific support that I am aware of. My personal point of view (based on me only) is that this probably does apply to newer divers that might not be diaphragm breathing and hence are taking shallower breaths.
    3. Some claim that diving Nitrox is safer. Again the view is mixed. If you dive Nitrox based on air tables then yes, there is an additional safety factor. This is however, quite small as the air tables themselves are already conservative. The debate is whether this marginal "safety benefit" is offset by the negatives that I set out below. Also, if you dive to the no deco limit of Nitrox, then there is no additional safety when compared to diving air to the no deco limit.

    So basically, only benefit number 1 is undisputed.

    In terms of drawbacks;
    1. You need to know what is in your tank. Therefore before each dive you spend about 20 seconds analyzing and marking the tank contents onto the tank.
    2. Nitrox (and air) have a maximum safe depth that they can be used at for recreational purposes. You need to make sure not to exceed your tank's maximum depth. This is the key risk as prolonged exposure to higher partial pressures of oxygen can cause Central Nervous System (CNS) toxicity and lead to underwater convulsions. There is, however, a lot of safety built into the Nitrox usage as you will learn it and therefore if you follow the rules, you will be fine.
    3. Prolonged exposure to higher concentrations of oxygen can cause your lungs to become rough. This will repair itself once you stop diving. It is highly unlikely that you will be able to do enough recreational dives to have a problem. I was diving 5 or 6 dives of 45 to 60 mins a day for a week in Bonaire and didn't come close to an issue.
    4. Nitrox fills can be more expensive.

    So as I said at the outset, to my mind the knowledge and ability to use Nitrox are worth the course.

    Galapagos in 3 weeks. . . cool. I have not been there myself, but have heard that the diving can be difficult with currents and surge. Be careful and try stick close to the guide.

    Bonaire . . . more cool. I have dived there and benefitted tremendously from being able to do 5 dives a day on Nitrox. Conditions were easy and well suited to a new diver. The shop I used gave a fee upgrade to Nitrox, so it was a no brainer.
     
  10. KWS

    KWS ScubaBoard Supporter ScubaBoard Supporter

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    just do it , you wont regret it. everyone responds differently to it. i feel less tired and get more bottom time, orthers get no advantage. the theory of it will get you going for years of thought and gives you the background for a lot of the discussions of more advanced arenas of diving. you can do it online and for all practical in the big picture it is free training. if you dont like it , you dont have to use it. but if you do , it is great stuff. I will say for me that when on it i have to be carefull not to leave the others in the group beind when gong from pint a to b. i just dont feel fatigued. I am 60 for all prectical purposes. i dont have the physical capabilities of a 20-30. i can understand that jocks probably will see no endurance benifit. for me it is day and night. i get 20-30% more dive time. i think i breath probably 1 breath perminute slower when on it. perhaps its imagination, i dont know. but i am first in and last out of the water when on it. if you are going to do many dives a day you will feel much better at the end.

    Some draw backs. cost, using it with a non notrox buddy. having to figure fequivilant air depth( or jsut use the nitrox computer and forget it).

    If you are ever considering gong into "technical diving" then advanced nitrox will be a snap. Get a dive planner that will show you the compartments saturations and compare the air vs nitrox and you will see what the body is dealing with. a cheap one is on dive nav its called dive planner andn for 7 bucks you can incorporate nitrox and trimix to compare. you can play with docompression and watch the pregresive results. Using it is like smoking you think nothing about it but if you could simulate smoking and watch the body o2 levels and respiraton rates and heart rates you see things differently. would i use it to plan a dive, i dont know but its fun to play with after you read about such things as nitrox pros and cons and various deco stratagies and the like. test things out on your desk top. info is info...
     
  11. Doomnova

    Doomnova Nassau Grouper

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    Get it one day you'll be doing 4-6 dives a day for a few days and there is no sense in spending a ton of money and banging your head against the NDL on the second day.
     
  12. Bubbletrubble

    Bubbletrubble Regular of the Pub

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    Get the nitrox cert at your earliest convenience. You'll definitely want to take advantage of using nitrox when you are diving Bonaire. Many dive ops on the island give a "free" upgrade to nitrox, so you might as well use it.

    t-mac opined that your Galapagos trip will be a "once-in-a-lifetime" trip. Since you're already located in Ecuador, the trip to the Galapagos really isn't too far from home. I'd guess that, if you have a good time on this trip, you'll be back for more later. Considering your experience level, it might be best to discuss with your dive op the possibility of visiting easier/more sheltered sites. You can save the more challenging/exposed sites featuring strong currents for later dive trips when your skills are better and you have more experience.

    Have a great time on your upcoming dive vacations!
     
  13. Teller

    Teller Scuba Instructor

    # of Dives: I'm a Fish!
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    More O2 equals more BT and less SI. These are the biggest reasons to use nitrox for the recreational diver.
     
  14. t-mac

    t-mac Barracuda

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    Location: VA, USA
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    Okay, so maybe not once-in-a lifetime for the Galapagos for you -- we should all be so lucky to be so close to such fantastic diving. Still, it will be an expensive trip (you don't own the dive op, do you? :D) and you will want it for Bonaire too and the point is the same. Anyway, seems like the unanimous opinion is to do it! Have a great time!
     
  15. h90

    h90 Manta Ray

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    If cheap...do it, but the advantages aren't as great as they tell you.
    No, or not much benefit on shallow dives. Can't be used on real deep dives. Less tired on the end of the day: If everyone is repeating it and believing it, than maybe...Placebo effect....
    But specially if you dive more than 2 times per day, there are big benefits.
     
  16. offthewall1

    offthewall1 Scuba Instructor

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    Nitrox - ?

    Nitrox has a place in recreational diving but not everyone needs it and not everyone will benefit from it.

    Preface: I'm a Scuba Instructor with ratings from 4 agencies (and teach Nitrox,) a former dive shop owner, current commercial dive business owner, with more than 3000 dives. With all that said, others will disagree with what I'm about to say... so take what I say - and what they say - into consideration... and then make your own decision.

    Nitrox can increase either bottom time or your safety factor, but not both at the same time. In other words, you can stay down longer using Nitrox then you can on air due to the increase in the partial pressure of oxygen in the mixture, however if you use this extra bottom time, the end result of nitrogen in your system is the same as it would have been on air in a slightly shorter dive.

    The alternative is to dive Nitrox, but to dive the same profile as you would have using air. The same depth and the same time. Doing this builds in a greater safety factor by reducing the amount of Nitrogen in your body.

    The limiting factor of Nitrox is the MOD or maximum operating depth. Nitrox is not for deeper diving. In fact, the higher percentage of Oxygen can become toxic at depth and kill you. For this reason I do not advise new divers to use Nitrox until they have mastered buoyancy. I further advise that they do not use Nitrox on wall dives or blue water dives where it is easy to lose track of depth. I have seen more than one diver drift deeper than their planned dive... in each case luckily they were just on air... which caused Nitrogen Narcosis. While this is bad, it's fix is easy - simply ascend, and with the help of others, they were safely escorted to shallower depth and the condition resolved itself. Had they been using Nitrox, they most likely would have convulsed and died from oxygen toxicity.

    It is important to understand the risks vs the rewards. Too many of my scubaboard buddies simply throw out - YES, GET NITROX. The fact of the matter is I've been diving safely for 15 years... and while I'm Nitrox certified and certified to teach it - I have not dove it since 2003. I simply don't see significant benefit vs. cost and danger.

    Most people I know who dive it do so for the safety factor moreso than the extended bottom time. They don't admit it... but it is obvious. When they dive Nitrox and I dive air - on the same wrecks, we all get in and out of the water at the same time. Yes, I often have to do a decompression stop because I'm on air - but I've come to enjoy these. Over the years some of the coolest things I've seen in the open ocean have come by while hanging on the line.

    In any event, consider everything and then make your decision. You really won't be wrong either way... Just understand the proper way to dive and practice your skills.

    Happy and Safe Diving.
     
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  17. WB2GLP

    WB2GLP Scuba Instructor

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    Roberto, are you and your wife diving with computers? Are they capable of adjusting for nitrox? Having the flexibility to dive with nitrox is a big benefit, but having a computer to fully realize the advantages should be your first concern. If you have them good. If not, that should be your first step.

    Since you're new to diving, I would encourage you both to take a traditional course that will include a couple dives under the supervision of an instructor rather than going the online route. Asking a web app how to program your computer for 32% is pretty difficult, especially while on a dive boat or a desolate beach on Bonaire.
     
  18. TSandM

    TSandM Missed and loved by many.

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    Dive Bug Bit Me summarized it pretty well, but I'd like to add a couple of things.

    Nitrox is not for deep diving -- the benefits of it are most relevant in the middle recreational range, between 60 and 100 feet. Below 100, you have to use such a light mix that your increased no-deco time is not substantial; above 60 feet, your no-deco time will often exceed the time you can manage on the gas you have.

    Nitrox IS excellent for trips where you are doing multiple dives per day, over multiple days. Even those 50 and 60 foot dives can add up under those circumstances.

    In addition, taking the Nitrox class will review your OW instruction about decompression, which is never a bad thing.
     
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  19. Saxatilis

    Saxatilis Nassau Grouper

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    Agreed on the no brainer comments. I also agree that if you find yourself most limited by NDL nitrox will be a big help. However, I don't feel that diving nitrox leaves you less tired than diving air. I know a lot of other divers who do feel that way though. Even so, I make a lot of dives to the 60-130 fsw range and it really does help your NDL particularly in the shallower ranges.

    Watch your MOD and dive safe!
     
  20. jhayes75

    jhayes75 Photographer

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    Partially true, the end result at depth would be about the same, but you will off gas quicker because of the increased oxygen intake during your accent and safety stop. So you will have less Nitrogen in your blood once on the boat than you would with just 21%. This is why your computer or tables will show a lesser time frame for surface intervals.
     

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