Another Great trip- need advice on nitrox cert.

[Qnape]

Just back from Little Cayman and heading back to Coz in April. I got my enriched air cert a few years ago, but Reef Divers at LCBR has a good policy; take the Nitrox course on arrival and get free fills for the trip. They do this for reasons mentioned above; they get a lot of older divers, and many are doing at least three dives a day. They want to minimize whatever risks they can.

Cheap, no. Nitrox fills at LCBR are priced about the same as at Coz, but only 32% is available.

 

[mjatkins]

Just wanted to weigh in with a few points. First, you will need an instructor to teach you the practical portion of the Nitrox course, assuming that you do the PADI course. A divemaster is not qualified to do it. Also, please be clear that the PADI online course will not earn you a certification unless you also do the practical portion with an instructor, and there will be an additional fee for that. The online class is only a portion of the course. In my opinion, you are better to not do the online version. It is quite expensive, to the point of costing more than most places charge for the full course.

 

[Ron Lee]

My dive computers are Suunto. Reportedly they are more conservative (allow less time) than other dive computers. Actually I think on my last trip I did verify that underwater. Diving with Aldora we have longer dive times than typical with AL80 tanks. That is partially mitigated by a longer surface interval on a beach. Still, I have encountered second dives where I have to ascend (not surface) sooner than the main group to avoid going into deco. This is using air and a square profile site around 60'.

As an aside, it is why I am not fond of Santa Rosa as a second dive.

Obviously, using nitrox makes this scenario less of a problem.

I refuse to use nitrox on the first dive since I feel that needing to go deep is a higher probability event and I do not want the depth limitation imposed by nitrox.

 

[Christi]

Just wanted to weigh in with a few points. First, you will need an instructor to teach you the practical portion of the Nitrox course, assuming that you do the PADI course. A divemaster is not qualified to do it. Also, please be clear that the PADI online course will not earn you a certification unless you also do the practical portion with an instructor, and there will be an additional fee for that. The online class is only a portion of the course. In my opinion, you are better to not do the online version. It is quite expensive, to the point of costing more than most places charge for the full course.

This is what I actually encourage people to do who are heading down and considering the nitrox course online - but some people want to get most of it done before they get here and don't care about the additional cost.

If I know far enough in advance, I can actually send the book to the student so reading and knowledge reviews can be completed before arriving. If not, then I can give the book here upon arrival and we do the practical portion of the course on day two or three - depending on how fast of a reader the student is - it's only about 80 real pages of reading by the time you take all of the pretty pictures into consideration And yes, we can do this for a much more economical price than paying the PADI e-learning and then doing the practical portion here.

 

[Butch Fries]

Just got certified for nitrox after about 16 years of diving air; it's interesting that the PADI course book stresses that there's actually no benefit in terms of DCS....but then PADI is terrified of implying that there's anything less safe about air diving.

 

[DandyDon]

Just got certified for nitrox after about 16 years of diving air; it's interesting that the PADI course book stresses that there's actually no benefit in terms of DCS....but then PADI is terrified of implying that there's anything less safe about air diving.

DAN does not suggest Nitrox is safer. Hypothetically it is, as less N2 loading is less, but it's a complex issue. Hits are so rare, it's hard to define what causes them.

 

[Butch Fries]

I actually got DCS a year ago and the attending doctor recommended I switch to nitrox, so I was surprised when I read PADI's claim in the course book that there isn't any proven benefit.

 

[DandyDon]

I actually got DCS a year ago and the attending doctor recommended I switch to nitrox, so I was surprised when I read PADI's claim in the course book that there isn't any proven benefit.

Which doctor gave that advice?

 

[Karibelle]

Just got certified for nitrox after about 16 years of diving air; it's interesting that the PADI course book stresses that there's actually no benefit in terms of DCS....but then PADI is terrified of implying that there's anything less safe about air diving.

I believe that what the PADI manual says is that using enriched air to reduce your nitrogen exposure, while still using an air computer, can be an attractive option for individuals you are subject to one or more factors that make DCS more likely. And presumably, if you've suffered from DCS, then you are one of those individuals.

And if PADI DID tout enriched air as safer option than air, what a wonderful opportunity that would be to sell the course. They haven't done that, you're right.

kari

 

[Mossman]

DAN does not suggest Nitrox is safer. Hypothetically it is, as less N2 loading is less, but it's a complex issue. Hits are so rare, it's hard to define what causes them.

To clarify, you and Butch Fries are talking about diving nitrox on air tables/computer. There is a definite benefit in terms of DCS when comparing nitrox NDC dives to air dives of the same profile because on the air dives, one would have a much higher risk of getting bent if mandatory deco stops were skipped.

Diving nitrox on air tables means less nitrogen loading because the partial pressure of nitrogen is lower and also faster off-gassing from the higher oxygen partial pressure. Physiologically, less saturated tissues will be less likely to cause bubbling issues leading to DCS. The problem is in the proof, since, as you say, hits are so rare. There simply isn't enough data to scientifically prove this physiological truism, especially since what little data does exist is likely flawed due to misdiagnosed DCS (doctors jumping to incorrect conclusions) and undiagnosed DCS (divers who fail to seek treatment for mild DCS).

I have more faith in our knowledge of physiology than flawed statistics so I often dive nitrox even if air would have enable the same NDC profile.