"Accidental" Deco

[Rhone Man]

To my knowledge, there is NO system using depth averaging that has undergone any significant formal testing and documentation.

What are you saying about ratio deco? :shocked2:

 

[aquaregia]

I think there's a pretty distinct difference between "significant testing and documentation" and "a bunch of dudes do it and it works just fine".

 

[Splitlip]

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.

2 weeks ago one, of my infrequent buddies went into deco without knowing it. I only found out this past Saturday that he had bent his computer the previous week. I did not get to review his computer's log Saturday because his service called before we docked. One of his surgery patients was having problems with his sutures.

In any event, 2 weeks ago, Buddy was making his first dives in more than a year. He did not have his Eanx card, so he was only able to rent air. He normally dives single al 80's with ~36%. On a two tank trip, volume of gas is usually the limiting factor, not NDL's.

I thumbed the second dive of the day on that trip because of a mask problem. Buddy had a brain fart on that dive. Hooked up with another friend using 36% and simply over stayed, not recognizing RBT changed to deco.

He is fine, but did bend his computer. I have yet to check the log.

 

[Bubbletrubble]

2 weeks ago one, of my infrequent buddies went into deco without knowing it. I only found out this past Saturday that he had bent his computer the previous week. I did not get to review his computer's log Saturday because his service called before we docked. One of his surgery patients was having problems with his sutures.

Surgeons are notorious for being the "dumb jocks" of the medical world. Cut first...ask questions later. Any complicated post-op medical issue is farmed out to the "other" team (internal medicine, ID fellows, etc.).

I do understand the point you're trying to make is that even smart people can make boneheaded mistakes, such as incurring an unintentional deco obligation. However, I think it's another level of stupidity entirely to then "bend" the computer by surfacing without fulfilling that deco obligation.

 

[scubadiveilat]

Surely! Things can happen however most important rule is to plan your dive and dive your plan.A real simple rule. Errors should be foreseen. Never exceed your limits and those of others.

Diving is a very safe sport. Unless the human error exceeds the limitation.

Scuba dive and have fun!!!

 

[scubadada]

This is a polite forum, I shall comply. Sorry, but I do not see any reasonable explanation for unexpected deco. Watch your computer and gauges. I often push deco and end up with a very short obligation that disappears on assent or requires less time than the safety stop. On the rare occasion I push further, I know I have an obligation to hang at the shallow stop for a finite amount of time and known that I have sufficient gas to fulfill that obligation. You are responsible for yourself, heed that responsibility.

Good diving, Craig

 

[Mr Carcharodon]

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?

It is really a good idea to have a plan in case you do run over. Not that you should, but having a contingency plan is a good idea. Take a look at the 1984 Navy dive table (which you can likely find on the internet) and see if you can find a relationship between max depth and bottom time. The table also gives decompression times if you run over and you can likely build some bounding cases to cover yourself. Of course the 1984 Navy table may not be fully current today (i.e. it is not considered conservative enough) so pad a bit and just use it as a point of departure.

 

[ozzydamo]

there are basicaly two kinds of people in the world:
1. people who let things happen to them
2. people who control what happens to them

My homage to Jeff Foxworthy

1. If you routinely run out of gas in your car, diving may not be for you
2. If you told the cop you got drunk accidentally, diving may not be for you
3. If you are easily distracted by shiny objects, diving may not be for you
4. If you thought "Hitler is not AOW" was a training video....

I am sure there are a lot more. This is where a mentor or the old guy needs to pull said diver aside and have "the talk" and see if the divers in question can be fixed or not.
Eric

And 9billion real human beings who oscillate between those 2 "parameters", 2 sizes do not fit all, life isn't black or white-
Generalisms lead to bigotry, this is hard to fix.

 

[AbyssalPlains]

Yes, an untrained diver should not go into deco. However, if you do acquire a one or two minute ceiling, it's not a big deal. It will usually clear after a slow ascent. If not, you do a 5-minute safety stop instead of a 3-minute safety stop. You will live to dive again.

What he said. Relax and take a deep breath. Your basic attitude is great - that divers should stay within their limits - but with time and experience, you may find that stuff that sounds extremely dangerous and/or reckless at first can be less dramatic when encountered in reality with some experience.

For example, i was once on a deep dive (135 feet max) with a friend who was an advanced diver with moderate experience. We were following down a line at a submerged dam in a lake. Due to the lake's plankton levels, it was completely dark at depth and we used our lights to keep track of things. Suddenly he shot up like a missile. I went after him, but decided to let him go as he was going up the line, and saw his light dangling back and forth and getting dimmer as he went up.

My other buddy and I started to ascend ourselves, but slowly. Back on the boat, we asked our third buddy what happened. He replied, I looked at my computer and discovered that I had only one minute of NDL left. That freaked me out.

With a bit more experience and perhaps a couple or so times of "accidentally going into deco" he would have known that racking up a deco obligation of a few minutes will a) most likely clear during a nice and slow ascent and safety stop, and b) put you in deco for a short time at 3 meters at most. Instead, he risked a rapid ascent injury because he did not know what to expect.

 

[Centrals]

With a bit more experience and perhaps a couple or so times of "accidentally going into deco" he would have known that racking up a deco obligation of a few minutes will a) most likely clear during a nice and slow ascent and safety stop, and b) put you in deco for a short time at 3 meters at most. Instead, he risked a rapid ascent injury because he did not know what to expect.

I have been told repeatedly in OW and AOW classes the danger of DCS as well as dive well within the limit(ndl) BUT never what to do IF...... Decompression is absolutely NO.
I do believe many divers are unprepared for the thought of deco stop.
Computer has complicated the ndl because of different settings and theories.