Do you think computers encourage risky diving in new/ young divers?

[Eric Sedletzky]

I’m in this group you’re talking about. I have not taken a decompression course, I routinely exceed my computers decompression limits, and I do not calculate my remaining air. I would probably not behave this way if I was diving square profile tables!

It seems safe-ish though. When I hit deco at depth I start heading up, and the deco goes away as I do. I slowly ride my computers warning up to the surface, do my non-mandatory safety stop with 1000#, and it and I are both happy on the surface. If I misjudged things a bit I’ve had two or three minutes of real deco at 10’, but that’s more of an extended safety stop than an underwater emergency, right? I have never been close to a situation where I did not have enough gas to make it back up, even if I can’t quantify how close.

Safety is only one of the factors to be optimized here: I dive for fun and would be much safer just staying in bed all day. It’s my (limited!) understanding that spending most of the dive slowly ascending up a wall or wreck is easier on my body than a square up-and-down profile anyway. Diving like this allows me to cover a lot of different terrain, see a lot of different things, and decide what to do based on what I see down there rather than following a fixed plan. The fun / danger ratio seems high, even if I can’t quantify the fun either. Do I just not know what I don’t know? Are there things I haven’t considered? Would I learn those things in a deco course?

What this is is just “flying your computer”. Many people do this these days. They give full trust to their DC to take care of them and ride the line without really giving much thought to what’s going on with gas reserve/depth/time. Computers have relieved a lot of the burden and trouble of having to think and pay attention to what’s going on, they do everything for you, probably way better and more accurately than you could do on your own. I suppose that could be a problem in the wrong hands; being used by people who have very little understanding of basic deco theory.
I can’t/won’t say it’s right or wrong, it seems to just be a sign of the times, people trust their lives more and more on machinery and devices.
Will it bite you in the ass someday? Maybe...If you’re going to trust your life on a device, at least make sure it’s a good one and learn how to use it well.

 

[lermontov]

The whole thing is just way too casual. The practical training and understanding of decompression obligations is there to give us the building blocks to make the right choices that cover a gamut of variables from deco mixes to exposure suits.
To just take a computer read out dive as you go is asking for trouble it's also conditioning you to normalise deviation, you'll probably get away with it with dives down to 30m. beyond that your rolling the dice.

Should the day come when it all goes wrong will you have the knowledge and more importantly the understanding to make what could be life saving decisions.
Do you understand the effects of cold on decompression times?
Do you understand what Gradient factors are and how to adjust for a particular dive with say current or workload, tiredness, how many deco dives youve done lately.
Would you comfortable making decision on the fly to change your G/ F if you had to get out off the water
do you know what the best mixes are and why?
could you do all this and look after a buddy whos in distress at the same time?
and if really gets serious and you have to surface - how many minutes of deco can you risk missing ? do you have 02 on the boat?

Its better to get some training

 

[TMHeimer]

Answer to the OP: No.

I regularly lead inexperienced divers on local dives after they get their open water certifications, so I see a good sampling of the species.

New divers are so focused on the basics of seeing, breathing, getting neutral and getting horizontal under water that they are unaware of the information available on their computers or what it means. Most will not check their depth or pressure without prompting.

Today was a typical example. Young couple around 30 years old. They've been certified two years and they already have eight dives (now ten), including the four in their OW course. They looked at their consoles only when asked to do so. I don't believe either of them processed any information other than tank pressure during the length of our two dives. I guarantee they weren't thinking of ways to game the computer.

Overall, this couple was very normal for new divers. We talked about their responsibilities to themselves and each other, but from the moment their brains came in contact with the salt water, they stopped giving evidence that they were doing any planning or thinking. They were counting on me to keep them safe and in contact with each other in our 15-ft visibility. I did. They tipped well, and they want to go out with me again, at which time, I'll try to get them to broaden their perspective from the diameter of a drinking straw to that of the core of a toilet paper roll.

It takes time to develop maintain situational awareness of the variables that affect your dive.

A new or young diver who tried to use a computer to maximize deep bottom time and ride the NDL up as described in the OP would be unusually precocious.

I agree with your last sentence about that being unusually precocious.
I have only DMd for OW courses, and rarely have dived with new divers (other than when me and my then -- and only regular-- buddy were both new). I am surprised to hear that the norm you have experienced is that new divers rarely check their depth and pressure. I believe you of course. I would think that being new would mean going overboard looking at one's consule/computer. Maybe that's because that's what I did back then-- and still do today though most of my dives are shallower than 30'. The old OCD I guess.

 

[Scraps]

I agree with your last sentence about that being unusually precocious.
I have only DMd for OW courses, and rarely have dived with new divers (other than when me and my then -- and only regular-- buddy were both new). I am surprised to hear that the norm you have experienced is that new divers rarely check their depth and pressure. I believe you of course. I would think that being new would mean going overboard looking at one's consule/computer. Maybe that's because that's what I did back then-- and still do today though most of my dives are shallower than 30'. The old OCD I guess.

It's not just completely new divers. I took a group of certified AOW divers to a private freshwater dive site that offers a dip to 100' along a fixed line. In the pre-dive brief, it became apparent they didn't understand exactly what NDL meant or how it changed throughout a dive. So I suggested we to stop every ten feet on the down and on the way back up so everyone could check their NDL and see how it moved from 99 down into the teens and then back up to big numbers.

Afterwards, they seemed pretty excited to have learned what that large font number on their screen signified.

I hope I didn't spawn a new group of NDL-surfing unqualified decompression divers!

 

[Edward3c]

Good morning.
...
I can be extremely academic at times, and find the question "Somewhat vague."

You can't argue with arithmetic. I mean absolutely "No." offence to you. It's just how my mind works.

Cheers.

Unfortunately, life (and diving) isn’t straight cut. Most guidance - particularly deco theory (as that’s all it is) - came about from trial and error, just read Jacques Cousteau’s “The Silent World” for near misses.

Or give the quizes posted by @Pedro Burrito a try,

 

[wstorms]

The biggest problem I've seen with new divers and computers is the perception that NDL is black and white. There is a neat countdown to 0. The thinking is something like "above 0 your are totally fine, below 0 you are totally screwed, so when it's down to 1 I simply ascent as quick as possible and this will keep me safe because the little display told me so"...
Obviously this is a lack of understanding of both computers and deco, and is probably at least as risky as having to stop for a minute (and clear that in the the slow ascent).
Like others said, computers can provide valuable info, but you still need to understand what that info represents.

 

[kelemvor]

Something I've been curious about. If I exceed NDL my computer will tell me to stop at X depth for Y minutes. After that it will tell me next stop depth and time. I have not tried it but my understanding is that it will show one stop at a time. It will not tell me all stops ie, will not tell me the air needed in total.


Do you experienced divers think that the fact that the computer will "get you out of deco" in any way encourages newer/younger divers to exceed their training and experience?

Do seat belts encourage risky driving of automobiles?

IMO, the answer to both is no.

 

[Edward3c]

Do seat belts encourage risky driving of automobiles?.

That's a tricky one.

I personally believe a spike in the centre of the steering wheel would be more effective.

 

[formernuke]

That's a tricky one.

I personally believe a spike in the centre of the steering wheel would be more effective.

Please no, I would have 2 extra holes from getting rear ended at a stop.

 

[johndiver999]

Please no, I would have 2 extra holes from getting rear ended at a stop.

TWO extra holes! ??? You must be getting rear ended pretty hard!