first deco dive

[Garth]

I dove the oriskany and did a technical deep dive. Recreational divers on the boat did there first dive first then we entered. We finished and they splashed after there SI.
One of the recreational divers thought there computer said he had 5 minutes of no deco limit. Actually said he was in 5 minutes of deco already.
How it turned out.
He ran out of air on his 39 minutes of deco! Luckily the DM on the boat stayed calm and had enough air on his back plus a al40 handed down to help.
What you did was unplanned and although it was very much less of an emergency it was reckless is some amount IMO.
I'm amazed at how many people run out of air and this is often the case with long unplanned deco. Either that or you break you ceiling. Neither is desired.

 

[Dr Wu]

Decompression diving is not difficult but some of it is counter intuitive.

Like anything you should probably get some decent training before you try that again.

 

[h90]

I dove the oriskany and did a technical deep dive. Recreational divers on the boat did there first dive first then we entered. We finished and they splashed after there SI.
One of the recreational divers thought there computer said he had 5 minutes of no deco limit. Actually said he was in 5 minutes of deco already.
How it turned out.
He ran out of air on his 39 minutes of deco! Luckily the DM on the boat stayed calm and had enough air on his back plus a al40 handed down to help.
What you did was unplanned and although it was very much less of an emergency it was reckless is some amount IMO.
I'm amazed at how many people run out of air and this is often the case with long unplanned deco. Either that or you break you ceiling. Neither is desired.

39 min of deco.....how can this happen????
First of all you need to have a basic idea of you deep and times even without computer.
He must have seen the computer counting down 5,4,3,2,1,0 and that up again till 39????
39 min deco must be a long time at great deep

No one can be that silly, or??

 

[h90]

I think a few min. deco isn't a problem in a good buddy team with enough air.
just following the computer.
But everything above 5 min should be planed before and the equipment should be right for it.

 

[Garth]

The recreational fellow who did this performed two deeper dives on the Oriskany. He was on Air for both and his computer I believe was a Mares of some sort. It was a tid bit scary really. A few of my teamates were about ready to start handing down our deco bottles to help but they made it through it.
5 minutes into deco at 120 ft thinking you have 5 minutes until deco at 120ft... not priceless.
...
rather reckless. everyone makes mistakes it just seemed a major one that's all.

 

[Garth]

39 min of deco.....how can this happen????
First of all you need to have a basic idea of you deep and times even without computer.
He must have seen the computer counting down 5,4,3,2,1,0 and that up again till 39????
39 min deco must be a long time at great deep

No one can be that silly, or??

are you suggesting that everyone looks at there computer every minute. I know i check mine often but we wouldn't be telling stories of such stupidity if these people were looking out for themselves the way you suggest.

 

[Blackwood]

are you suggesting that everyone looks at there computer every minute. I know i check mine often but we wouldn't be telling stories of such stupidity if these people were looking out for themselves the way you suggest.

It seems unlikely to me that a (presumably) single tank diver will have enough gas to incur a 40 minute obligation. I may be able to do it with a 120 and no current. Course then I won't have any gas left for deco, but I digress

Sounds like a computer malfunction to me from this comfy armchair.

 

[DevonDiver]

39 min of deco.....how can this happen????
First of all you need to have a basic idea of you deep and times even without computer.
He must have seen the computer counting down 5,4,3,2,1,0 and that up again till 39????
39 min deco must be a long time at great deep

No one can be that silly, or??

I guess you've never been in that situation. Most divers are aware, and expect, the deco to reduce (or at least not increase) as you ascend. That is not always the case....

Having accidentally gone 5 minutes into deco, the diver can begin ascent and still find their deco obligation rising fast. It can really catch you out. It can also almost feel like the deco is being added exponentially...with every extra minute on the bottom, or ascent, adding many extra minutes to the deco.

It all depends on what tissue compartments are being loaded at the time...and consequently used for the deco. Most recreational divers who hit a small amount of accidental deco are only familiar with the quickest tissue comparments getting loaded...and those clear fast also. When the slower compartments start to control the deco... then a lot of time starts getting added fast...

It happened to me (accidentally) just once... when I pushed limits spearfishing barracuda at 30m. I pushed right to the limit of NDL before ascent. On ascent, I had to pause for a while and sort out my fish (there was an issue with nearby sharks etc). That pause put me into deco. By the time I had got to the surface, I had 14 minutes of deco....and only enough air to complete 9 minutes of that. Got on the boat, sucked O2....and got away with it

 

[kanonfodr]

I'm not a deco-trained diver, but I trust no little black box on my wrist to give me a proper decompression schedule. If it was that easy, everyone would be doing decompression dives safely. Get the free version of V-Planner and play around with it a bit, see what profiles it spits out for different exposures.

But please, if you plan to do more "decompression" diving, please get trained! We recently had a local fish collector bite the big one from a DCS hit. He was not deco trained (or rebreather trained, which just so happened to be what he was using for that dive) and he suffered a lot before his body went ahead and shut down on him.

Peace,
Greg

 

[snowmaker]

It seems unlikely to me that a (presumably) single tank diver will have enough gas to incur a 40 minute obligation. I may be able to do it with a 120 and no current. Course then I won't have any gas left for deco, but I digress

Sounds like a computer malfunction to me from this comfy armchair.

Depending on his computer and whether this was his first, second or even third dive of the day it could happen. Some computers, not designed for deco, will really penalize you on multiply dives. Some will not give you credit for off gassing as you ascend until you hit the required stop. If you incur deco and it tell you your first stop is 10' but you stop at anything below that for added safety the computer may continue to add deco time.