PADI Deep Specialty

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Re: PADI Deep Specialty

Postby Drip » Tue May 11, 2010 7:39 pm

...have you got your Nitrox cert yet GoatFish? I recommend this as very useful to have.
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Re: PADI Deep Specialty

Postby ChuckyBob » Tue May 11, 2010 9:58 pm

In my experience it was very useful for 2 things.
1. Its a prerequisit for advanced nitrox ( which goes hand in hand with deco procedures)
2. It was great to use nitrox on a 5 day live aboard diving the Lermi.
Other than that I have only ever done 2 nitrox dives ( make that 4 including the course) and there was no real benefit in using nitrox for those dives.

Nitrox course is one that IMHO is totally theory. You dont dive any different. There are no special skills required. Simply set your computer to the correct gas mix or use the correct tables and plan the dive accordingly.
If you are considering a Nitrox course read this page. If you can understand it then do the cheapest course you can. If you cant then re read it until you do.
http://www.gasdiving.co.uk/pages/misc/Nitrox.htm
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Re: PADI Deep Specialty

Postby guru » Wed May 12, 2010 8:39 am

Awesome discussion guys!
It's great to see so many options and great advice that is more focused around the results than the actual syllabus.

Now for my blatant hijack and to throw some more discussion out there. If I am a diver who is after more bottom time at depth (Either more time between 15-30m or someone interested in pushing past 30m, discuss both :) ), is it worth to start looking at a Nitrox course or a deco course? What are the results to expect from each?
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Re: PADI Deep Specialty

Postby Andy » Wed May 12, 2010 10:49 am

ChuckyBob wrote:Nitrox course is one that IMHO is totally theory. You dont dive any different. There are no special skills required. Simply set your computer to the correct gas mix or use the correct tables and plan the dive accordingly.
If you are considering a Nitrox course read this page. If you can understand it then do the cheapest course you can. If you cant then re read it until you do.



I would tend to disagree - hey, why change the habit of a lifetime! :lol:

Nitrox theory isn't difficult, and is possibly "over-done" in many nitrox courses. Though it will be interesting to see how things change with the latest revision to the PADI course that now no longer requires tables use.... I have to be honest, I am dismayed at that! A "to the letter" nitrox course would take about 2 hours to teach if there are no tables questions.

Personally, I won't teach nitrox without tables - or without dives. Whilst there are no specific skills on the nitrox dives, they do provide you with an opportunity to add value. For example, focusing on buoyancy control. In the past, I've been sneaky and dived a different mix than a student - which produces a challenge in terms of managing MODs (and also checking whether a student is blindly following you) and improving situational awareness... and standardisation of gasses, along with the simplifications that brings. I tend to teach depth averaging in a nitrox course and getting people into the habit of keeping track of their average depth and no-deco limits in their head during the dive.

I think it's a freakin' awesome course... and well worth hunting around to find a good one to do, rather than the cheapest one available.



guru wrote:Now for my blatant hijack and to throw some more discussion out there. If I am a diver who is after more bottom time at depth (Either more time between 15-30m or someone interested in pushing past 30m, discuss both :) ), is it worth to start looking at a Nitrox course or a deco course? What are the results to expect from each?


To my mind, there isn't really much point in doing a deco course unless you are wanting to do accelerated deco using nitrox >40%. It's not so bad at places like the Poor Knights where there is something to look at whilst doing deco, but straight hang time in blue water (say after a wreck dive) is just dull, mind numbing tedium. I want to cut that time to a minimum, so using a rich mix to do that is the way to go.

To do an advanced nitrox course to let you use up to 100% O2, you need to be basic nitrox qualified - though some agencies and instructors will allow you to combine those courses.

Shallower than 18m, there isn't much point to nitrox. NDLs are exponential, so you get way more time shallower than you do deep. For most divers, air consumption is likely to be the controlling factor for a dive shallower than 18m. Below 18m, the deco models start penalising you quite severely (as an aside, this is one of the main reasons that agencies recommend new divers stay 18m or shallower) and using nitrox in that 18-30m range is great.

Deeper than 30m, you start getting into a grey area - is the use of a mix like EAN25 really worth it, or are you better off diving air and using a rich nitrox mix to accelerate deco? The only real way to answer that question (for you) is to run some profiles in software like DecoPlanner or Vplanner and see what the impact is on your run time. We do a lot of that sort of analysis on our deco courses. Somewhere between 30-55m you will find that people will start to edge towards using trimix rather than air as a backgas - where that line is drawn depends on a lot of factors, and there is no real "right" answer for anything other than the individual in question.
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Re: PADI Deep Specialty

Postby guru » Wed May 12, 2010 1:06 pm

ChuckyBob wrote:http://www.gasdiving.co.uk/pages/misc/Nitrox.htm


This makes for some quite good reading!
It certainly brings a lot more into consideration and I can see where tables for this type of diving would really have an impact. It would be interesting to know if a all Nitrox computers also included maximum bottom times & depths for your oxygen toxicity levels / pressure, or if they just re-calculated your effective depth compared to air.

Andy wrote:To my mind, there isn't really much point in doing a deco course unless you are wanting to do accelerated deco using nitrox >40%.


Thanks for all the information Andy! As always, you provide so much to consider. I wasn't just talking for myself, although I am considering it, but for all who are interested in extending bottom times for different depths.
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Re: PADI Deep Specialty

Postby ChuckyBob » Wed May 12, 2010 1:44 pm

Andy wrote:

I would tend to disagree - hey, why change the habit of a lifetime! :lol: ...........


What you are talking about are skills not taught in a nitrox course. Now you may teach them but then you may also teach them in other courses. But when I did my course the instructor didnt even join us for the dive. If the student wants to improve buoyancy then a PPB course would be better.
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Re: PADI Deep Specialty

Postby Andy » Wed May 12, 2010 2:10 pm

ChuckyBob wrote:What you are talking about are skills not taught in a nitrox course. Now you may teach them but then you may also teach them in other courses. But when I did my course the instructor didnt even join us for the dive. If the student wants to improve buoyancy then a PPB course would be better.


Am I allowed to draw a big red circle around that, then a big red circle around your previous comment about "pick the cheapest course available" and draw a line between them?? :lol:

I'm not getting at you, Greg.... but sometimes you do get what you pay for. I harp on a lot about value, and this is a really good example.

Unless you blend it yourself, you do need a nitrox cert to get nitrox fills. Picking approximate prices out of thin air, a nitrox course would typically be priced at around $250. As you've pointed out, you don't have to do the dives and therefore if a diver wanted to get to dive with nitrox and do a buoyancy class, they'd pay another $200 or so for a buoyancy class. For the sake of argument, let's say that it's all shore diving so there are no boat costs.

What would you rather do, pay that $450 for two courses (again, let's assume that it's a good PPB class that teaches something about buoyancy) or pay $400 for a nitrox class that gave you the same skills?

As has been pointed out a few times, minimum standards are just that - they are the absolute minimums that need to be covered in a course. It is not the sum total of what should be covered in a course. There is a worldwide, agency-wide trend for instructors to consider the courses as inviolate things that never change - irrespective of the students doing the course, which often ends up in a square-peg round-hole disillusionment. Adding value is about treating every course differently, understanding that all students are different - and have different aspirations.

I acknowledge there is a certain sales pitch here, but I think it's useful to give people an idea about the differences in all the courses available and how to sift through them to choose the right one. if that nudges people towards our courses then that's a bonus - but the main aim is get people to start thinking about the quality of the training they are looking for and choosing something that is right for them.

Take TDI AN&DP, for example. I did mine with Pete Mesley and paid $1200 for it at the time. This may seem more expensive... but as a simple exercise, let's see how much I paid per minute of in-water time. We did six dives of 90 minutes each, and then a seventh "graduation" dive of an hour - total of 600 minutes. So I was paying Pete $2 per hour of in water time (ignore lectures, materials etc).

TDI standards mandate a minimum of 100 minutes bottom time, so let's add 100 minutes of ascent/deco time to that. You could pay $700 for the course.... and then you are paying $3.50 per minute in water for a minimum standards course.

If that time in water is used constructively, going over skills, getting feedback, improving.... which one is better value?

And bear in mind that some instructors turn a blind eye to the bottom time requirement - the fastest I have heard of is about 35 minutes of bottom time (including ascent time, a total of about 60 minutes). And also recognise that in-water time needs to be spent doing something - if you're just floating around looking at the pretty fishes, then you might as well just go diving.
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Re: PADI Deep Specialty

Postby Drip » Wed May 12, 2010 3:00 pm

Nothing like a good 10-14m dive on 36% around Guerilla Bay's (Batemans Bay) little island outcrop for more than an hour (a 10 minute /5m safety stop thrown in) and emerging with that nice relaxed feeling, while others emerge somewhat bland and much earlier upon cheap air.
Personally I think there is a conspiracy and the Goverments are shipping cheap air in from China.
I try to incorporate Nitrox in any dive I do and if I can get away with a higher percentage, the better - though I will never compromise my safety by risking a toxicity hit by going below the recommended depth (no matter how much I love Nitrox).
I even breath on my Nitrox when doing those long/strenuous Shore Dive walks which leaves me again feeling relaxed and my muscles very well oxygenated whereas I should be huff'n n' puff'n and my leg muscles feeling the urge to tighten up ...like the others way behind me.

BREATH NITROX
BREATH NITROX
BREATH NITROX
BREATH NITROX
BREATH NITROX
BREATH NITROX
BREATH NITROX
BREATH NITROX
BREATH NITROX
BREATH NITROX
BREATH NITROX BREATH NITROX BREATH NITROX BREATH NITROX BREATH NITROX
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Re: PADI Deep Specialty

Postby binklebonk » Wed May 12, 2010 3:11 pm

Drip wrote:I even breath on my Nitrox when doing those long/strenuous Shore Dive walks which leaves me again feeling relaxed and my muscles very well oxygenated whereas I should be huff'n n' puff'n and my leg muscles feeling the urge to tighten up ...like the others way behind me.


Rubicon Research Repository wrote:Measurement of fatigue following 18 msw dry chamber dives breathing air or enriched air nitrox.

Many divers report less fatigue following diving breathing oxygen rich N2-O2 mixtures compared with breathing air. In this double blinded, randomized controlled study 11 divers breathed either air or Enriched Air Nitrox 36% (oxygen 36%, nitrogen 64%) during an 18 msw (281 kPa(a)) dry chamber dive for a bottom time of 40 minutes. Two periods of exercise were performed during the dive. Divers were assessed before and after each dive using the Multidimensional Fatigue Inventory-20, a visual analogue scale, Digit Span Tests, Stroop Tests, and Divers Health Survey (DHS). Diving to 18m produced no measurable difference in fatigue, attention levels, ability to concentrate or DHS scores, following dives using either breathing gas.


http://archive.rubicon-foundation.org/3975

It may be Drip, that you're just fitter than your mates. Or your expectation of an effect may be the causation of your anecdotal correlation between higher FO2 and "feeling good".... Or of course it could be that cheap Chinese air that the dive shops are importing online nowadays.. :D
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Re: PADI Deep Specialty

Postby ChuckyBob » Wed May 12, 2010 3:38 pm

Andy wrote:
Am I allowed to draw a big red circle around that, then a big red circle around your previous comment about "pick the cheapest course available" and draw a line between them?? :lol:



The point I was making is that you are more the exception than the rule Andy.
Most instructors I have dealt with are not interested in adding extra value.

So sure, if the instructor is willing to help the student out with other issues then its worth paying more for.
But if the student just wants a cert card for nitrox then I stand by what I said. As long as you understand the theory first then take the cheapest course you can.
I was quoted $95 for a PADI nitrox course with no dives.
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Re: PADI Deep Specialty

Postby Andy » Wed May 12, 2010 5:21 pm

ChuckyBob wrote:
Andy wrote:
Am I allowed to draw a big red circle around that, then a big red circle around your previous comment about "pick the cheapest course available" and draw a line between them?? :lol:



The point I was making is that you are more the exception than the rule Andy.


Aw, thanks Greg! :D

So sure, if the instructor is willing to help the student out with other issues then its worth paying more for.
But if the student just wants a cert card for nitrox then I stand by what I said. As long as you understand the theory first then take the cheapest course you can.


Yup, if you know your stuff then "buying a card" is a reasonable option. I am fairly open minded about different ways of learning and don't insist that training is the only way - mentoring and self-learning can be good options as well. Good training is probably best matched with those people who "don't know what they don't know".


I was quoted $95 for a PADI nitrox course with no dives.


This really scares me. The cost of the required materials alone is over that.... assuming they comply with the agency standards of what a student requires. So best case, the instructor is working for free (what incentive do they have to add value?) or they are happy to break standards (what other corners are they cutting?). :shock:
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Re: PADI Deep Specialty

Postby GoatFish » Wed May 12, 2010 5:41 pm

Well - there is so much to think about.. and this has been a very good discussion (a lot of which is currently above my head however I'l get there!)....

I have pretty mcuh decided that I won't look at doing the wreck course (just yet that is) as I am still happy being on guided tours with swimthroughs and very limited penetration.

I suppose I was more wanting to do a deep course so as to not limit myself on any dive site that is available to me 30m+ while out on charters... in saying that, whether the actual PADI Deep Specialty with give me the skills I need is up for debate.. as I have just been told by an instructor that I'll do three dives.. Dive (1) to 30m where I do navigation (swim in a straight line and back), and Dives (2) and (3) to anywhere between 30-40m looking at pressure and doing the narc test...
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Re: PADI Deep Specialty

Postby Paul » Wed May 12, 2010 6:37 pm

GoatFish wrote:I have pretty mcuh decided that I won't look at doing the wreck course (just yet that is) as I am still happy being on guided tours with swimthroughs and very limited penetration.


If your interest is wrecks, then certainly find a good wreck instructor. I personally do not like the idea of following someone through a wreck. What happens if something happens them? If you dive wrecks a bit, then you could certainly stand to gain alot of good stuff from a wreck course run by someone with a passion in that area.

I totally agree with Andy's viewpoint when it comes to training. The wreck course is no different, in that you could do a wreck course without ever swimming into a wreck or covering what I think would be essential skills for safe wreck diving. I think it's important to find out about your instructor, ask them what type of diving they do... you ask them for their log book :D to see what type of dives they actually do and not just talk about.

If you do it with a good instructor, you will get WAY more than what PADI define as minimum standards.
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Re: PADI Deep Specialty

Postby ChrisB » Wed May 12, 2010 7:27 pm

Paul wrote:If you do it with a good instructor, you will get WAY more than what PADI define as minimum standards.

ALL you have to do is find a GOOD instructor :D :D

I'd like to put my 2c here and say, the benefits of 'real world' training of diving inside wrecks, assuming thats what you're into, cannot be IMHO ignored blindly. Get yourself a good/great instructor with the right passions and you will get soo much more value for money. And they just might build in a lot of other course info that goes hand-in-hand and most importantly keeps you thinking, "am i safe??"

That said, I'll still looking for a GOOD instructor... :lol: :lol: kidding, i know a few more than worth their salt :shock: Andy
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Re: PADI Deep Specialty

Postby GoatFish » Wed May 12, 2010 7:32 pm

Paul wrote:
GoatFish wrote:I have pretty mcuh decided that I won't look at doing the wreck course (just yet that is) as I am still happy being on guided tours with swimthroughs and very limited penetration.


If your interest is wrecks, then certainly find a good wreck instructor. I personally do not like the idea of following someone through a wreck. What happens if something happens them? If you dive wrecks a bit, then you could certainly stand to gain alot of good stuff from a wreck course run by someone with a passion in that area.

I totally agree with Andy's viewpoint when it comes to training. The wreck course is no different, in that you could do a wreck course without ever swimming into a wreck or covering what I think would be essential skills for safe wreck diving. I think it's important to find out about your instructor, ask them what type of diving they do... you ask them for their log book :D to see what type of dives they actually do and not just talk about.

If you do it with a good instructor, you will get WAY more than what PADI define as minimum standards.


Yes, that is true... so I'm picking that Andy is a good instructor? :D
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