Nitrox 28 Uncertified

[buleetu]

is there that much of a differance to using 21% anyway, are u much more less likely to get dcs using EAN28 or is this why the higher amount mixes more widely used?

do people on holiday regularly have problems with dcs on the return flight home?

when i asked them (subex) about there recommended no fly time they said 24 hours, isint 18 hours the no fly time for normal compressed air repetitive dives, surely if the mix is 28% we would need a shorter si before flying

 

[spectrum]

is there that much of a difference to using 21% anyway

At 28 percent you can avoid some of the risk at the cost of some of the benefit. It's a little like a bicycle with training wheels. You may not fall down but a truck can still hit you.

are u less likely to get dcs using EAN28

Yes, any reduction in nitrogen exposure lowers risk. It's important to note that diving air as prescribed is already extremely safe.

do people on holiday regularly have problems with dcs on the return flight home?

Not routinely

when i asked them about there recommended no fly time they said 24 hours, isint 18 hours the no fly time for normal compressed air repetitive dives surely if the mix is 28% we would need a shorter SI before flying.

A common rule of thumb had been 24 hours. Recent research by DAN says that there is no measurable risk in going to 18 hours after a week of recreational diving. Those 6 hours can be a nice addition to the trip depending on your departure time.

Pete

 

[Jim Lapenta]

It looks like a great place for those with no brains and little common sense. And as James mentioned there are documented cases of divers taking hits at 1.3 and dying. They are full of crap. While it is not rocket science this is just another example of the dumbing down of courses and standards. Oh well Darwin loves this kind of stuff and it helps with the weeding out process.

As for the no-fly why take chances. I tell my students that 18 is the new recommendation but I advise them to wait for 24. That last 24 hours is the perfect time to pack, rest up, and go shopping for the souveniers you'll bring home to people who won't appreciate them anyway and you know it. But you get to rub it in their noses that they were stuck at home while you were diving.

 

[D_B]

I'm sorry but I have to disagree on one thing Jim, about this being another example of the dumbing down of courses and standards .... the point being made in this thread, here, is that there is no course, and no training, and no standards

Although, it may indicate some of the mindset out there that divers don't need to think

 

[H2Andy]

is there that much of a differance to using 21% anyway, are u much more less likely to get dcs using EAN28 or is this why the higher amount mixes more widely used?

if you don't know, should you be diving a mix you have no training on?

that's the issue: divers should know what they're getting into and have the knowledge necessary to make this sort of call

do i want to dive 28% on this dive? how do i know if i can? what's my MOD? what's my NDL? what's my cumulative O2 exposure gonna be?

if you can't answer those simple questions, then why are you diving that gas?

of course, when someone tells you: "you'll be fine diving this gas" you can just say, "oh, ok..." and go ahead and dive it

 

[flw]

Not read the rest of the thread - however - IF you are diving a site where there is a seabed within the MOD AND you are diving a single cylinder then why not - unless you are planning significant deco ( on a single?!) it's a safer gas - I've done exactly this with my kids, and would do it again

 

[H2Andy]

IF you are diving a site where there is a seabed within the MOD

again, how do you know what the MOD is or why that is important if you have no Nitrox training?

what we're objecting to is people diving a gas without even the basic tools of determining whether that gas is safe: what's its MOD? what's its NDL? how will it affect my cumulative O2 load? if i dive the next one on air, how is that going to work?

if you can answer those questions correctly, then i don't see a problem

and yes, you can learn this on your own ... but it might make sense to get a formal class under your belt and get certified before diving anything over 21%

as i said earlier, Nitrox is not rocket science ... you could probably learn all you need to learn in two hours ... with time to spare

 

[flw]

To be fair it was my daughter - she's a baby helicopter engineer, so has a reasonable grasp of both physics and chemistry (she's 18) and has grown up on dive boats in Shetland and Scapa Flow, so she probably has a better grasp of the essentials than most - but we were diving scapa about 35m, it is still a safer gas than air - and we'd just nipped accross on impulse, max pO2 of 1.4 - read O2 and the Diver!! - I'd do the same again

 

[H2Andy]

it is still a safer gas than air

how did you make that determination?

 

[flw]

how did you make that determination?

Using air tables and nitrox the chances of any dci are reduced significantly - we were doing 'no-stop' diving - we'd been climbing during the week and been weathered out, so done lots of hard excercise in the days previously - high-tailed it home and decided to go diving instead - the chances of a seizure occuring at pO2 less than 1.4 are very small, whilst staying well with 'no-stop' limits on squarish-profile' dives.
I've been on plenty of dives when there has been a hiccup with either proper bends or niggles - and I'm happy than she was as safe as can be on a cruiser in scapa flow