Why is PADI so conservative?

hi guys

im a padi open water diver

im just home from a diving trip and i was struck again by the ssi schools attitude to diving deeper than 18metres with an ow card

nearly every dive we done was in the 20-30 metre deep range and when i had a chat with a guide from the school about me having an 18 m card and wasnt allowed to go to 30metres he said that with ssi it isint this way at all, he said that the way he done it was to have a check dive then to see the skills of the diver and then make the decision as to what dives they are able to do

whats the differance between diving to 18m and to 30m, is it possible nitrogen narcosis and also not being able to directly ascend on one last breath of air, can someone do this from 18m by the way, it doesnt look to me as if i could do a cesa from that deep, what other issues are there when we dive below 18 m that we wouldnt have shallower than 18m

thanks guys

You have a young child.
You're visiting the Grand Canyon and walking along the edge.
How close to the edge would you like your child to walk?

the K

think of this at 18 meters you are at 58.5 ft [3 atmospheres. at 30 meters you are at 97.5 ft ] 5 atmospheres. That is a lot. nitrogen and bottom times are greatly changed and tanks are compressed so gas time is 25% less.. A big deference. Not to mention the fact that you can get narkeg too at 97.5 ft.

Skeeter1097:

think of this at 18 meters you are at 58.5 ft [3 atmospheres. at 30 meters you are at 97.5 ft ] 5 atmospheres. That is a lot. nitrogen and bottom times are greatly changed and tanks are compressed so gas time is 25% less.. A big deference. Not to mention the fact that you can get narkeg too at 97.5 ft.

Click to expand...

Small correction to the details;

20m = 3 ata
30m = 4 ata
1 atmosphere per 10m depth + 1 atmosphere for the surface air.

Best Regards
Richard

buleetu:

hi guys

im a padi open water diver

im just home from a diving trip and i was struck again by the ssi schools attitude to diving deeper than 18metres with an ow card

nearly every dive we done was in the 20-30 metre deep range and when i had a chat with a guide from the school about me having an 18 m card and wasnt allowed to go to 30metres he said that with ssi it isint this way at all, he said that the way he done it was to have a check dive then to see the skills of the diver and then make the decision as to what dives they are able to do

whats the differance between diving to 18m and to 30m, is it possible nitrogen narcosis and also not being able to directly ascend on one last breath of air, can someone do this from 18m by the way, it doesnt look to me as if i could do a cesa from that deep, what other issues are there when we dive below 18 m that we wouldnt have shallower than 18m

thanks guys

Click to expand...

Does your card specifically say that you are limited to diving to 18 meters?

No, you were told that you are certified to dive in conditions similar to those in which you were trained and have dove. Right?

Now, in the OW class, you dove no deeper than 18 meters, I am assuming. So, in your dives since then, have you struck strictly to 18 meters limit? Or did you occassionally exceed it to 18 or 20 meters? If so, then you would now be experienced, to some degree, at 20 meters. Thus, with a good dive buddy, you can slowly expand the depth and type of diving you are experienced in.

However, at this point, I would recommend a GOOD Advanced OW class to get you some more training now that you've got a few dives under your belt.

Good training and good dive buddies can help you get more and better dive experiences.

Good luck.

Ken

Hi there,

With regards to your query, it is not so much that PADI are overly conservative, a decent dive centre will insist that you stay within your limits. Also you will find that most insurance companies will only cover you to the depths of your certification (regardless of experience). The initial depth for BSAC divers is only 20m too. In fact most training agencies have a similar depth limit for their equivalent entry level courses.

If you wish to go deeper, you should do the training. The purpose of the advanced course, is to give you a little more experience in the diving field, ensuring that you improve your skills and confidence, are able to maintain buoyancy whilst task loading (for example whilst following a compass in your navigation dive, one of the compulsory dives), and also actually taking you to a depth where you are likely to experience some kind of narcosis, but in a controlled situation. Ie with an instructor, on a dive site with gentle conditions. Although the skill has now been changed to the colour change comparison, I always found the timed task a great eye opener, as most people don't realise that they are experiencing nitrogen narcosis until they see how much slower their timed task was underwater. You would not want to be at 30M on a wall dive and experiencing nitrogen narcosis for the first time (it is not always a pleasant sensation).

Ok so your experience now shows you have dived to 20M, however was that under the guidance of an instructor? Did you further your knowledge of decompression sickness prior to this dive? The mere fact that you ask the questions you do demonstrates that there is more for you to learn and understand regarding the factors that affect your personal depth limit.

I would say if you are hankering to head down a little deeper, just do the course (it only takes 2 days), and if you then get the urge to go deeper than that, do the next course.

Enjoy your diving...
All the best
DiveBunnie

Skeeter1097:

think of this at 18 meters you are at 58.5 ft [3 atmospheres. at 30 meters you are at 97.5 ft ] 5 atmospheres. That is a lot. nitrogen and bottom times are greatly changed and tanks are compressed so gas time is 25% less.. A big deference. Not to mention the fact that you can get narkeg too at 97.5 ft.

Click to expand...

More small correction to details, in addition to Riger's corrections above:

Tanks do not compress, you use more of the air at depth, but tanks do not compress.

You start getting narced when you begin your descent. The physical effects show up in different people at different depths, but the process itself begins immediately. Some people will show signs at a lot shallower depth than 4 atmospheres, some not until later...

There is no difference between PADI and SSI recommendations on the dive limits for divers.

Both agencies recommend that divers do not exceed the limits of the training and experience.

As an Open Water diver, you are only trained to dive to 18m. As a certified diver, you are responsible for your own dive planning and conduct. Therefore, if you exceed that depth then you are ignoring the agency recommendations.

The dive center is not responsible for any misfortune that may occur to you as a result of you exceeding the recommended limits.

The same is true for recommendations about diving in overhead environments or difficult conditions....as well as recommendations about diving in poor health, low fitness, dehydration etc etc etc etc etc

Some dive centers (PADI, SSI or whatever) apply those recommendations as a policy, because they wish to safeguard their customers and do not want to have to deal with incidents. Other dive centers let customers make their own decisions and have the liberty to dive as they want.

It is the perogative of the dive center to choose what limitations they wish to apply on customers.

IMHO, those divers who feel 'confident' to exceed their recommended limits are typically the ones who most need further education and a deeper understanding of the increasing risks that come with depth and overhead environments etc....

I've managed both SSI and PADI dive centers and imposed the same depth limitations at both.

starting out in any sport it is good to be conservative

after 100 dives, there's not much difference between diving to 60 feet or 120 feet

however, on your first few dives, you are still unsure of how narcosis will affect you at depth, unsure of your skills, and unsure of the environment. the deeper you go, the faster you go through air, so the faster emergencies get out of control.

it's a good thing to progress slowly and give yourself "artificial" limits to begin with as your experience and confidence grows. those limits can be imposed by the agency or be self-imposed.

I don't think the 18/60 depth has much to do with being able to do a CESA from there. I have read that some have done a CESA from even deeper. I asked my AOW instructor what you do if out of air and below the 30 feet you can do a CESA from, and he said you do a CESA (hopefully) anyway unless you absolutely need to ditch your weights.