"Accidental" Deco

[emoreira]

I was on a boat dive today and we had two people go into deco "accidentally". I am wondering how can you accidentally go into deco? I have had a few computers and they all say it as big as can be on the screen while you are diving how long you have until deco. If it gets low you head up as to not incur a required deco since as a basic diver you are not qualified to get into deco. I guess that this is just a big rant that if you cannot keep track of the few things that are required that you should not be diving. If you can't watch your gauges, don't go in the water. You become a hazard to not only yourself but to everyone that is with you on the dive. I don't really know any other way to get a persons attention that if you are not qualified for something don't do it. Plan your dive and dive your plan and you will live to do it again.

Though I do completely agree with your statements, a lot of good things happen because unqualified people do things they are not qualified to do. A lot more people die or get hurt because they do things they are not qualified to do.
Look at Jacques Custeau. He was inventing what we do now. He was not qualified to do what he was doing, he was directly inventing this sport.
Normaly I ran out of gas before entering deco.

 

[tr3a]

how do you know the Deco was accidental? or the qualifications/ experience of the divers? Just curious

 

[Hatul]

I was on a boat dive today and we had two people go into deco "accidentally". I am wondering how can you accidentally go into deco? I have had a few computers and they all say it as big as can be on the screen while you are diving how long you have until deco. If it gets low you head up as to not incur a required deco since as a basic diver you are not qualified to get into deco. I guess that this is just a big rant that if you cannot keep track of the few things that are required that you should not be diving. If you can't watch your gauges, don't go in the water. You become a hazard to not only yourself but to everyone that is with you on the dive. I don't really know any other way to get a persons attention that if you are not qualified for something don't do it. Plan your dive and dive your plan and you will live to do it again.

It's very easy. You go down and see you have a minute or two of no deco time and on the ascent your computer goes into deco. As you ascend until you get to a certain depth (the floor) some tissues continue to take on nitrogen and you cross into deco mode.

Adam

 

[eelnoraa]

This is all good informaiton. Accdental deco should be avoided as much as possible. With model dive computer, as long as the user keep their eyes on the NDL time, accidental deco should NOT happen.

Now, what happen if a diver only dive with gauge and a table? Let's say the dive plan the dive, and dive as close to the plan as possble. Say gas is not an issue, is there a way to double check if Deco is necessary based on average depth, max depth and bottom time. Is there another class I have to take to get this information?

 

[dbulmer]

Eelnora,
The simple answer to your question is to dive conservatively and respect the NDLS of the agency that trained you.

I understand your question perfectly but in all honesty the internet is not the place for discussing deco issues - your best bet would be to seek face to face instruction from an instructor who has proven experience and knowledge of decompression issues and that would mean you talking to someone who specialises in technical diving.

 

[aquaregia]

I always suspected that I didn't pay enough attention to the deco number on my computer. I watch the time and depth just fine, but I would sometimes realize that even though I looked, I didn't really read the NDL time. Probably 75% of my dives have been done on tables, and 90% of my computer dives have been for repetitive dive planning, rather than deeper dives. So usually I don't use my computer for NDL very much.

On one dive I'd recently looked at my depth, then my computer beeped. I knew I wasn't ascending, so it had to be the NDL. Sure enough, time to go up. Lesson learned.

 

[Jaydubya]

Very few cases of decompression obligations are truly accidental, i.e., caused by forces outside the diver's control.

IMO, any overhead diving (including mandatory decompression) without proper training and equipment is negligent. Frankly, I would not incur a deco obligation without a dual outlet gas supply. I have seen too many o-rings blow or regulators free flow to do otherwise.

 

[ajduplessis]

The poor guys, they surely must have been using Suunto's :gun:

 

[Rhone Man]

When I "accidently" go into deco it's on purpose. What's the big deal? Deco ain't rocket science, it's not some kinda mystery. It's like a saftey stop only longer and ya gota do it no excuses if you ain't got the gas you're SOL.

I suspect this may be the most common reason for these situations. Telling the anally retentive divemaster that you "accidentally" went into deco leads to less friction than saying "Actually, I am a properly trained diver and a grown-up, and I spit on your petty 'no-deco' rules."

Wow, that's surprising. Most basic divers don't have the gas to maintain a proper reserve and get into that sort of deco. What tanks were they diving? Were they day diving or was it a series of repetitve dives over multiple days? Were they diving Suuntos?

I doubt that we are talking about long deco hangs. Many of the "accidental decos" that I see involve just going a little past the NDL, and many actually clear during ascent. Those that don't usually only call for a short hang. Even the world's worst gas hog can spin out a short hang from 500 PSI on an Al80.

 

[TSandM]

eelnoraa, planning your dive with tables using maximum depth is standard practice, and should have been taught in your open water class. Using the tables in any other fashion is not using them as they were designed, and although there are some of us doing it, it is not necessarily a practice that can be defended in any other way than by saying that there are some of us doing it and getting way with it. To my knowledge, there is NO system using depth averaging that has undergone any significant formal testing and documentation.