Can you dive again after a minor Deco dive?

[ScubaAaron]

My dive buddy and I have differing opinions on this matter. He states that if you exceeded the no-deco bottom time on your computer, go into deco, then do the required stop(s) you are not allowed to dive again for 24 hrs. I am only talking about a few minutes deco. Is this correct? I believe that as long as you follow the stops per your computer and surface "not in deco" then you are OK to dive again.

And as a follow up: If I am correct and my buddy is wrong, is there any increased danger to going a few minutes into deco? As in increased bubbles? Other than if you do an emergency assend you will assend without doing the required stops.

Thanks in advance for your comments,

Aaron.

 

[chickdiver]

ScubaAaron once bubbled...
My dive buddy and I have differing opinions on this matter. He states that if you exceeded the no-deco bottom time on your computer, go into deco, then do the required stop(s) you are not allowed to dive again for 24 hrs. I am only talking about a few minutes deco. Is this correct? I believe that as long as you follow the stops per your computer and surface "not in deco" then you are OK to dive again.

And as a follow up: If I am correct and my buddy is wrong, is there any increased danger to going a few minutes into deco? As in increased bubbles? Other than if you do an emergency assend you will assend without doing the required stops.

Thanks in advance for your comments,

Aaron.

Provided you are following a proper deco schedule, and take a proper surface interval, then the answer is yes, repetetive deco dives are not only acceptable, but erformed all the time. However, following what the computer tells you does not necessarily count as a proper deco schedule. I would be happy to explain more in depth if you are interested.

 

[bradymsu]

I second what Chickdiversaid. Basically, you're both right, though I suspect he's more right. It depends on your training level.

If you are recreational divers and doing a recreational dive and happen to go into deco, you should stay out of the water for 24 hours. You should only be going into deco if you make a mistake. One of the very few bad things about computers are that they encourage recreational divers to do decompression dives without proper training.

DIVERS WITHOUT FORMAL DECOMPRESSION TRAINING SHOULD NOT BE DOING DECOMPRESSION DIVES.

If you are doing a technical dive, you can go into required decompression and then do a repetitive dive. However, technical diving means that you have planned your dive, decompression stops, contigency stops, gas needs, OTUs, etc. long before getting in the water using either decompression tables or technical dive planning software. If you're using a computer, it will likely be in gague mode, and it's very doubtful you'll be using the computer to tell you where and how long to do your stops.

 

[String]

Your buddy is totally wrong.

Every dive is a deco dive and tables or computers just set an arbitury figure for the NDL. There is no definitive right and wrong number.

You can quite happily do many deco dives a day if you want.

is there any increased danger to going a few minutes into deco? As in increased bubbles? Other than if you do an emergency assend you will assend without doing the required stops.

None what so ever. Provided stop schedules are adhered to, ascent rates are managed and air managment is ok there is nothing to be afraid of.

Deco diving isnt rocket science- if buoyancy control is good enough to safely hold stops there is no problem with it.

 

[BRW]

Folks,

Check out the new NAUI Tec Deco Tables for
various mixes. Depending on mix, depth,
altitude, exposure time, etc, TWO deco dives
separated by 3 hrs SI MIGHT be OK in a day.
Especially in the case of a "light deco"
first dive.

Every dive is actually a deco dive,
so that "deco is our friend, not our enemy".

This is quite apparent in diver training in
Europe (and elsewhere in developing arenas).
And folds into even rec RGBM Tables. So get
trained in deco procedures, mix optimization,
etc, even if you don't tec dive.

Bruce Wienke
Program Manager Computational Physics
C & C Dive Team Ldr

 

[ScubaAaron]

Wow, thanks for all the comments!

I see that people's views are quite different in this matter. To give you a little more information about my buddy and I we dive on air and are not looking to do technical diving. hat being said, I would like the option of extending my bottom times in some situations. My computer is rather conservative and at 90' I get 17 minutes NDL time. My buddy's computer gives him 25 (as does the PADI table I believe). So if I go to 90' for 23 minutes I'm in DECO mode. It does not go blank and only show depth, it apparently will show me what depth to go to and how long to stay until I'm "out" of DECO. Then I can surface safely.

Am I pushing the envelope too far?

 

[ReeseTD]

"My computer is rather conservative and at 90' I get 17 minutes NDL time. My buddy's computer gives him 25 (as does the PADI table I believe). So if I go to 90' for 23 minutes "


This is just my 0.02 but if you are with in the limits of your buddy's computer and PADI table then that is 2 of 3 sorces for you to go off of. I would however still follow your computer for deco stops since it will never kill you to do them.. but it could kill you if you dont do the stops. I like BRW post that ever dive is a deco dive even if you are not getting remotly close to NDL. I know that i need to work on take longer Deco stops and hay its just not time you get to stay in the water!!!

 

[Atticus]

1. You can certainly do rep deco dives (defining deco as a dive beyond the NDL).

2. There are sane ways to do this, usually involving precut schedules (though some deco on computer, and some using an algorithm in their head).

What I'm nervous about is that you're doing deco diving without redundant air sources, training, etc. Sure, by your buddies computer you're ok, but what happens when you and your buddy get separated? Are you really in deco? Or is your computer still just being "overly" conservative? Can you ascend immediately right now? Let's say the recall signal was just sent ...

I'd suggest that you trade in your computer for one that more closely matches your buddies, or vice versa.

Alternatively you could memorize the tables and dive them (much easily than it sounds using a summation rule (search for "rule of 120").

Yes, every dive involves decompression, but there is a huge difference between "deco diving" and "ndl diving". Let's not get hung up in the terminology.

 

[Karl_in_Calif]

ScubaAaron once bubbled...
... if I go to 90' for 23 minutes I'm in DECO mode. It does not go blank and only show depth, it apparently will show me what depth to go to and how long to stay until I'm "out" of DECO. Then I can surface safely.

Am I pushing the envelope too far?

Generally, going into deco, resulting in a ceiling and a required deco obligation, per your computer would be pushing the envelope too far for single tank NDL diving. Definitely.

I dont have my own Suunto here, so I cant play with this example of yours and see what it gives for your particular dive profile. It is odd that your computer and your buddy's give such different read-outs.

I will ascend normally several minutes before my NDL time is up, based on my computer, if not sooner. And I do not care what someone else's computer says. You are not obliged to stay down longer with someone else just because your buddy's dive computer says he can.

When we go into deco, we have preplanned our dive, we have redundancy in all our systems, we have practiced failure scenarios in training, we have slated our planned profile and a few alternatives, etc. We do not just go into deco "on the fly". And you should not either, ever.

The rest of your question, about diving again after having a "minor" deco incident, all depends on how you handled the first incident. A reverse profile, for one thing, would be a really bad idea after a deco incident. So if you kept your subsequent depth shallower than the first dive, and follow all the other advice that Chickdiver gave you above, you should be ok for a repetitive dive.

Chickdiver is a technical instructor, and she teaches topics like this, so she would be one of your best sources, from a NAUI perspective at least.

 

[cornfed]

Karl_in_Calif once bubbled...

I dont have my own Suunto here, so I cant play with this example of yours and see what it gives for your particular dive profile. It is odd that your computer and your buddy's give such different read-outs.

There is nothing strange about this at all.

Different computers, different algorithms, differerent answers.

PADI's tables don't agree with SSI's tables, so why would you expect two different computers to agree?