Going deeper, safely

[eternaljonah]

I am new to diving and have no plan to do some thing crazy, but i wish to understand, from what i read bounce diving is unsafe,but i don't full understand all what makes a bounce dive a bounce dive, one thing is the single tank, right?
But what about lets say doing 50m or 165 feet. With a tank of ean 28-32 and a tank or 2 of air(ean 21) And having a dive plan and deco info all calculated before, and more experianced divers along, Is that too considered unsafe, or is that just tec diving.

Lastly is having the skill doing a padi or ssi course or can one get those skills from other experienced divers and taking small steps, with in you capasity.

I don't want to start a discussion about this course or that course, or how to kill yourself. But one about how to stay alive, be safely and intellegently ,slowly learn to go deeper.

 

[wedivebc]

Going deeper than recreational can be done quite safely with proper training, equipment and most importantly experience. Yes this discipline is known as tech diving. There is a different name for bounce diving to 165ft on a single 80cuft tank and that is stupid.
You are smart to ask the question but please don't be in a hurry to get there. The journey is half the fun.

 

[DevonDiver]

I don't want to start a discussion about this course or that course, or how to kill yourself. But one about how to stay alive, be safely and intellegently ,slowly learn to go deeper.

Don't do dives that you don't understand - and acknowledge there is plenty you won't understand.

Don't confuse confidence with over-confidence.

Dive conservatively. If unsure, don't do it.

Plan your dives properly - NDL, gas and all applicable contingencies (doing so will eliminate most deep diving ideas)

Remember that a plastic cert card won't save your life if something goes wrong at depth - your ability to dive deep isn't determined by a qualification, it is dictated by your relevant experience, training, knowledge and preparedness.

 

[knowone]

An amazing buzz after skirting the fringe on boats and at club meetings and during seemingly incalculable amounts of dives, to be by an upper echelon of dive professionals, eventually invited to join them

 

[MXGratefulDiver]

I don't want to start a discussion about this course or that course, or how to kill yourself. But one about how to stay alive, be safely and intellegently ,slowly learn to go deeper.

First off, the basis upon which safe diving is founded is good decision-making. The genesis of many ... if not most ... diving accidents can be traced back to decisions that were made before the divers ever got in the water. This is particularly true for deep diving, because the deeper you go the more important it becomes to be able to avoid problems, or be able to solve them underwater. That ability comes with knowledge, foresight, and preparedness ... all of which you get better at through practice. This isn't a concept unique to scuba diving ... it applies to just about everything we do in life.

So ... with that in mind ... what does a prudent diver need to descend to 165 feet and return safely to the surface ... without putting undue reliance on Luck to get them there? They need the ability to answer the following questions ...

- Am I fit to do this dive? This question applies to both your mental and physical condition. You don't have to be an athlete to do deeper dives ... but you do have to recognize that depth puts stresses on your body, and the deeper you go the greater those stresses become. You need to understand what those stresses are and have adequate understanding of how they affect you to determine whether or not you meet the criteria. Mentally you have to be fit enough to be able to deal with unexpected situations calmly, and deal with them without undue stress. Stress is not your friend underwater, and the deeper you go the more important it becomes to be able to manage it while focusing on dealing with whatever unexpected circumstance you may encounter.

- Do I have the proper equipment? Not all recreational scuba geat can handle the demands of a dive below recreational depths ... it's just not what it was designed for. Now let's acknowledge that scuba gear is, for the most part, incredibly reliable and robust ... but recreational gear was built for recreational depths. Going below those depths can put a strain on your equipment ... particularly certain regulators ... that it simply wasn't designed for. You may be OK ... and maybe not. The biggest potential "gotchya" here is a regulator that's either incapable of handling the density of your breathing gas at that depth or hasn't been serviced properly (or recently). Increased work of breathing leads to CO2 buildup, and that's bad ju-ju at 165 feet.

- Do I have appropriate breathing gas? You mentioned EAN28-32 ... those are completely inappropriate gases for that depth. At 165 feet you're at 6 atmospheres of pressure ... that's a PPO2 of nearly 1.7 ATA's for EAN28, and in excess of 1.9 ATAs for EAN32. Those are much higher than the recommended upper limit of 1.4 ATAs for safe diving. Will you be OK at those levels? Probably ... but pushing your safety margins increases your risk of an oxtox event that would certainly kill you. Why take that risk, when choosing a more appropriate gas would prevent it. Additional questions about your breathing gas would involve "Do I have enough gas?" and "What would I do if I had a freeflow or other failure that caused me to lose gas?" The answer to the first question would be to calculate how much gas you'd need to bring ... with appropriate reserves for emergencies ... and assure that your cylinders could accommodate it. The answer to the second question is redundancy ... in whatever form you decided was appropriate.

These are the minimal questions I would recommend you seek answers to before attempting such a dive. You don't have to take a course ... but frankly, I can write whole articles answering each one ... and even those articles wouldn't give you all the information you might need to be able to make an informed decision whether or not making such a dive would be a good idea.

... Bob (Grateful Diver)

 

[Colliam7]

Don't do dives that you don't understand - and acknowledge there is plenty you won't understand. . . . Dive conservatively. If unsure, don't do it. . . . Plan your dives properly - NDL, gas and all applicable contingencies (doing so will eliminate most deep diving ideas)

the basis upon which safe diving is founded is good decision-making. The genesis of many ... if not most ... diving accidents can be traced back to decisions that were made before the divers ever got in the water. . . . They need the ability to answer the following questions ...
- Am I fit to do this dive?
- Do I have the proper equipment?
- Do I have appropriate breathing gas?
"Do I have enough gas?"
"What would I do if I had a freeflow or other failure that caused me to lose gas?"

I have to wonder if these thoughful comments reflect the kind of 'adult' discussion that Halemano was trying to stimulate in another thread that was quickly closed (' there is no such way to make this diving safe, and no more point in discussing unsafe practices '). Maybe not, maybe there was some agenda in his OP that I didn't see, etc. But, I have been disappointed in several recent threads where a question about deep, deep / air, or deep / air / 'bounce' diving has generated an immediate, emotional / visceral reaction somewhat akin to 'The question is stupid, and you must be stupid for even asking it.' I appreciate Andy and Bob taking a somewhat different apprao0ch and basically saying, 'For any dive, good decision-making is critical, and here are some of the questions / issues that should be addresed as part of good decision making'. My experience with four children (the youngest of which nominally concluded her 'teenage' years with a birthday two weeks ago) is that the surest way to get a teenager to do something that you don't think they should do is to tell them, 'That is stupid.' or 'You would be stupid to do that'. And, I made that mistake more than a few times. What worked better was to take the approach, 'Interesting question. If I was thinking about doing that, here are the questions I would ask and answer first first', or something to that effect - not foolproof, but a better way to get them to ask more questions (before heading off to do something I considered to be really stupid. ).

So, I compliment Andy and Bob, irrespective of what may have been their initial subjective reaction to the OP, for approaching the issue from a more thoughtful perspective. Yes, this is an Internet forum, and people are free to respond to posts any way (within certain limits) they want, and saying that something is 'stupid' is part of that freedom. But, that response shuts off discussion, and closing threads does the same thing (and, yes, I do understand - and don't disagree with - all the rationale about not promoting unsafe practices, blah, blah, blah). I would rather see us say, 'Personally, I think [whatever behavior is under discussion] is potentially unwise / unsafe / ill-advised, because it violates fundamental practices of good decision-making, such as . . .' than to simply dismiss it as stupid, no matter how tempting that might be, or to simply say 'get more training', without saying what or why.

 

[eternaljonah]

thanks for sharing your thoughts .... i was actually thinking that ean28-32 would be used for the decompression on the way up since i noticed a while back when i went over my ndl by 2 min that when i was on air(ean21) my suunto added 11 min of safety stop between 6-3m while when doing the same on ean33 i had only 3 min added so i figured that it would be good to do deco stops on higher oxygen mixes..

just to make it clear i am not attempting such a dive but really enjoy thinking about how one would do it safely, as as said above make it back to the surface i recently climbed a peak of 6300m, but had been dreaming, training and planning since more than 3 years....

 

[MXGratefulDiver]

I have to wonder if these thoughful comments reflect the kind of 'adult' discussion that Halemano was trying to stimulate in another thread that was quickly closed (' there is no such way to make this diving safe, and no more point in discussing unsafe practices '). Maybe not, maybe there was some agenda in his OP that I didn't see, etc.

I think the difference is due to ...

1. How the question gets asked.
2. The history of similar past discussions with the person doing the asking.

This OP approaches the subject by asking what it takes, rather than making assumptions about what it doesn't need. This OP also doesn't have a history of making up insulting terms for people who express differences of opinion. In that respect, his query is worth the time and effort to attempt a constructive ... "adult" ... discussion of the topic.

Those, at least, are my reasons for putting some thought into the response ...

... Bob (Grateful Diver)

 

[MXGratefulDiver]

thanks for sharing your thoughts .... i was actually thinking that ean28-32 would be used for the decompression on the way up since i noticed a while back when i went over my ndl by 2 min that when i was on air(ean21) my suunto added 11 min of safety stop between 6-3m while when doing the same on ean33 i had only 3 min added so i figured that it would be good to do deco stops on higher oxygen mixes..

While the concept is correct, the mixtures probably wouldn't provide enough benefit to be worthwhile. This is why people using deco mixes for dives in that depth range will typically use EAN50 or 100% O2 for their deco. Use of those mixes require a basic understanding of why and how you would want to use them ... a topic that can be learned without taking a class ("Deco for Divers" by Mark Powell would be an excellent source), but learned more in the context of the dive by taking an Advanced Nitrox/Deco class.

just to make it clear i am not attempting such a dive but really enjoy thinking about how one would do it safely, as as said above make it back to the surface i recently climbed a peak of 6300m, but had been dreaming, training and planning since more than 3 years....

Think of deep diving in a similar context ... in fact, I think that could be a very good comparison. Any idiot can walk up a mountain. Doing a peak like that and returning safely, however, requires some understanding of the risks involved, and some practice at the skills one would need to (for example) avoid falling into a crevice or arrest a slide down an ice field.

... Bob (Grateful Diver)

 

[DevonDiver]

thanks for sharing your thoughts .... i was actually thinking that ean28-32 would be used for the decompression on the way up

Deco needs specific training. It also demands an exceptionally high standard of core dive skills. High percentage oxygen mixtures are used, but it's the tip of a very big iceberg in terms of skills, planning and preparation.

A recreational nitrox course does not cover accelerated decompression procedures in any way. It's a big leap from where you are into deco diving.

Suggest you do some basic research here on SB, so that you understand the fundamental difference between a safety stop and an emergency deco stop.

i noticed a while back when i went over my ndl by 2 min that when i was on air(ean21)

my suunto added 11 min of safety stop between 6-3m while when doing the same on ean33 i had only 3 min added so i figured that it would be good to do deco stops on higher oxygen mixes..

just to make it clear i am not attempting such a dive...

But you're already going into deco situations. Very foolhardy... and precisely why NWGratefuldiver and myself gave the advice that we did.

You don't have much respect for the dangers of being in a deco situation. I'd suggest a visit to your local hyperbaric chamber to remedy this, they'll have more than a few first-hand stories about blown deco and the medical repercussions. Have the respect... really.

but really enjoy thinking about how one would do it safely, as as said above make it back to the surface

Basically... everything you're not doing now. Conservatism, planning, education, education, education, training, training, patience, conservatism...and RESPECT for depth/deco.