DECO the Dark site in recreational Diving

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Remy B.

Contributor
Messages
915
Reaction score
107
Location
Rotterdam
# of dives
200 - 499
As you see I'm a rucky diver, but I like to learn with good facts and opinions and rational , positive and educated answers, and polite answers, if any feel that this is not possible, you are egocentric or you find just a stupid post, please ignore this post, I don't need a negative or troll answer, I'm here for the positive learning in educated interaction, I'm kind of expectiving negative comments but please address them in good manners.

I always been attracted by the underwater world so I make one of my goals to become true, and I experienced diving and got certified, OW + AOW, great instructors, great great experince.

During both of my courses dive tables were addressed.

But the message behind the learning was keep it recreational diving the moment you want to get in DECO it stops been recreational, kind of a bad mojo type thing.

Unfortunadly I'm more curious on what is deeper down, I do enjoy watch fish but at the end they are what they are and I like structures, wrecks normally they are deeper, but I really like to take my time to observe, and I'm limited by the DC Alarm telling me you are 4 min from DECO and it gets more pushy whe I get the 2 min from DECO, I always keeping an eye on my air press but I make good ( or maybe bad ) use of my air and end up with I believe enough air at the end of the dive always above the 1000psi, the last 4 dives my instructors hit the 1/2 tank rule before me.

I know I can stay longer down deep and enter DECO and still have enough air, yes I know you will always want to have enough air reserve in case something go south on you, but now days dive equipment is more safer and actually it appear it can't get beyond what your 1st and 2nd stage regulators are safe wise, there is no improvements further to be done from what already exist exept of creating a complete new different setup.

With that mention, I agree yes still something can get wrong, in if sh... hits the fan while in DECO the chances are bigger to get hurt or be fish food.

But why I should get in DECO to stay a little longer down deep, knowing I still will have enough air at the end of the dive, I just find limiting the time you can enjoy down there by the DECO.

I see my self getting into TEC diving just to spent more time deep down, if money wise I'm ablento go that direction.

I have saw comments here in SB about you need to be certified or trained to do DECO, I'm not saying there is nothing to learn additionaly, but are not the famous Dive Tables already tell you as well as your DC how much time you need to DECOpress and all the teaching in OW and AOW about the DECO and the safety aspect as well as the negatives of not do one.

I have the impresion ( maybe wrong ) that DECO is a bad thing to do or only allowed by TEC, but if I have enough air to spend 10 more minutes down there, why I should not do that, I'm not looking to make a rutine of doing so just to be clear.

Thanks for your light in this, hope comments and opinions are plased in profesional and educated manner.
 
Deco's not bad, good, or anything else: it's the point where, theoretically speaking, physics and physiology require you to choose between a direct ascent to the surface and not getting bent.

What follows from that simple fact (plus the knowledge that sometimes unexpected problems arise) is why NDL vs. deco is generally pointed at as a brightline that's only crossed with training. Whether that's a formal class or something else is the subject of debate, but basically you don't go into deco without having a plan for how to get back to the surface safely no matter what goes wrong.

Case in point: during a staged deco dive fairly early in my diving career, I had spent 30 minutes at 190' on air and had a substantial decompression obligation. Just before starting my ascent, I found my Atomic Cobalt - a very fancy computer capable of handling deco diving with nary a problem - flooded and died in a spectacular fashion. I didn't care much, because I had my ascent profile written down on wetnotes in my pocket, plus a watch, a marked ascent line, and a backup SW Petrel on my wrist. But if that had been my only computer...I'd have been left with no way of determining my deco schedule, time, and depth, necessary information to ascend safely.

If you need it to complete a safe ascent--buoyancy, gas, light, guideline, time, depth, deco info, whatever--you don't go into deco without a plan for it failing. And knowing you'll actually be able to execute your plan.
 
I'm sure you will get detailed answers from tech divers, but let me approach this as a "sport diver" who has done deco dives before the word "tech diving" existed.

Once you pass beyond the No Decompression Limits you have placed an invisible but entirely real "barrier" between yourself and the surface. If, for any reason you are unable to complete your decompression obligation before crossing that invisible barrier, the risk is great, and the physical consequences are serious, painful, potentially crippling, and possibly even fatal.

I have a friend, now an ex-diver, who now spends most of his day in a wheelchair. With effort, he can stand up, using crutches, but has nearly zero ability to use his legs. Most people who see him assume he had a spinal injury or polio. His symptoms were caused by the bends back in the 1980's.

Having "enough air" to complete your mandatory decompression, and understanding how to complete the required decompression is not the hard part about deco diving. It is understanding and preparing for (as much as possible), the various things that could go wrong, and being able to calmly and correctly handle problems underwater and still complete your decompression obligation.

Standard recreational dive training does not prepare you for decompression diving.

Move forward into this type diving slowly, and only after being fully prepared.... "having enough air" is just part of it.

Best wishes.
 
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As you see I'm a rucky diver, but I like to learn with good facts and opinions and rational , positive and educated answers, and polite answers, if any feel that this is not possible, you are egocentric or you find just a stupid post, please ignore this post, I don't need a negative or troll answer, I'm here for the positive learning in educated interaction, I'm kind of expectiving negative comments but please address them in good manners.

I always been attracted by the underwater world so I make one of my goals to become true, and I experienced diving and got certified, OW + AOW, great instructors, great great experince.

During both of my courses dive tables were addressed.

But the message behind the learning was keep it recreational diving the moment you want to get in DECO it stops been recreational, kind of a bad mojo type thing.

Unfortunadly I'm more curious on what is deeper down, I do enjoy watch fish but at the end they are what they are and I like structures, wrecks normally they are deeper, but I really like to take my time to observe, and I'm limited by the DC Alarm telling me you are 4 min from DECO and it gets more pushy whe I get the 2 min from DECO, I always keeping an eye on my air press but I make good ( or maybe bad ) use of my air and end up with I believe enough air at the end of the dive always above the 1000psi, the last 4 dives my instructors hit the 1/2 tank rule before me.

I know I can stay longer down deep and enter DECO and still have enough air, yes I know you will always want to have enough air reserve in case something go south on you, but now days dive equipment is more safer and actually it appear it can't get beyond what your 1st and 2nd stage regulators are safe wise, there is no improvements further to be done from what already exist exept of creating a complete new different setup.

With that mention, I agree yes still something can get wrong, in if sh... hits the fan while in DECO the chances are bigger to get hurt or be fish food.

But why I should get in DECO to stay a little longer down deep, knowing I still will have enough air at the end of the dive, I just find limiting the time you can enjoy down there by the DECO.

I see my self getting into TEC diving just to spent more time deep down, if money wise I'm ablento go that direction.

I have saw comments here in SB about you need to be certified or trained to do DECO, I'm not saying there is nothing to learn additionaly, but are not the famous Dive Tables already tell you as well as your DC how much time you need to DECOpress and all the teaching in OW and AOW about the DECO and the safety aspect as well as the negatives of not do one.

I have the impresion ( maybe wrong ) that DECO is a bad thing to do or only allowed by TEC, but if I have enough air to spend 10 more minutes down there, why I should not do that, I'm not looking to make a rutine of doing so just to be clear.

Thanks for your light in this, hope comments and opinions are plased in profesional and educated manner.

This is pretty simple. Go piece by piece and say "if this breaks, what happens?"

Lets say you've stayed down long enough to get a 10min mandatory deco obligation. Now your reg fails. You're boned, bro. The surface is really your only option, and with a trip to the surface comes a very real chance of taking a trip to the chamber immediately following.

What if your computer that you're relying on breaks? Boned again.

If you have enough air to stay at depth for the additional time, how do you know you have enough to complete the deco? Out of air = boned.

Lose your mask and can't see your gauge? Boned. Inflator sticks open? Boned. Read some tables and use the info incorrectly because you aren't trained? Boned. Get delayed at depth causing your deco time to be longer than you planned (you do know how to calculate how much gas you need, right)? BONED.

See a trend?

Deco diving is neat. Go get trained.
 
Another option, if you haven't already, is to look into Nitrox to help extend your bottom times.
 
The line be deco and no deco is not a line at all but a wide fuzzy grey zone. Some times it is 10 or more minutes wide between conservative and liberal sets of limits. Some times it is only a few minutes. Wandering 5 or more minutes into deco does not need to be risky if you understand your gas supply and you have a good conceptual model of how the deco racks up and where and how long to decompress. For that matter wandering five minutes into deco on one table may keep you within NDL on another table. The risks of wandering a little bit over the line are not as much as portrayed in OW training but if you can’t quantify the risk and do not have a plan don't go there (but if you have that covered...). Do also think a few steps ahead. You may be OK now, but on the second dive?
 
This is pretty simple. Go piece by piece and say "if this breaks, what happens?"

Lets say you've stayed down long enough to get a 10min mandatory deco obligation. Now your reg fails. You're boned, bro. The surface is really your only option, and with a trip to the surface comes a very real chance of taking a trip to the chamber immediately following.

What if your computer that you're relying on breaks? Boned again.

If you have enough air to stay at depth for the additional time, how do you know you have enough to complete the deco? Out of air = boned.

Lose your mask and can't see your gauge? Boned. Inflator sticks open? Boned. Read some tables and use the info incorrectly because you aren't trained? Boned. Get delayed at depth causing your deco time to be longer than you planned (you do know how to calculate how much gas you need, right)? BONED.

See a trend?

Deco diving is neat. Go get trained.

I see that I made a mistake in my OP regarding depth, because I did not mentioned and it lead to confusion, I'm just staying in the 35m range

And the event all that you mention happen together, it is just your day to be fish food not even TEC courses will safe you from all that

So let see if I understood, if your regulator and your octo go bad as well, and you have only one one tank (normally recreation setup ), beeing TEC certified will not get you bend ??? Don't think so.

Another mistake of my part, is that I didn't mention that I dive with a watch as well for timing backup, in case my DC take a dump.

if your DC go bad, and you know the dive tables and have watch, and know at what depts to stop and for how long and you just put an extra time at that dept because you didn't take a look for 2min before you notice the DC went sought on you, plus you put another extra time at your second stop, is there something they teach wrong in OW and AOW regarding the tables and the stops.

I know I have enough air because I know the times requiered in the dive tables, and my DC does the safety stops and the same depths sometimes deeper sometimes not so deep, in two oportunities the DC told me to do safety stops at 13m depth and the regular 5m depth, both same time 3min and 2min "in those dives" ( I know it can be different depending ) ended up with 1300 and 1200psi respectively, 60min and 45min dives, depths between 25 and 35m, and looking at the tables the DECO times were very similar, so I Know I have enough air if sh.. don't hit the fan, I can see the confusion I created by not mentioning the depths that I normally are in to.

I know TEC dive have to do as well with redundancy, more than one tank, 1set of regulators per tanks and more redundant things, and a lot of more calculations, gas mixes and knowledge that is not presented on the recreational levels.

Again I know the dangers of the DCS, it was mention many times during my courses, and to stay inside my NDL and why.

Sorry for my mistake I assumed wrong that if I mentioned AOW it was pointing out to not get beyond the 35m , with the following conditions, one tank of air, knowing the dive tables and time tracking and depth, and knowing I have enough air to do my DECO stops.

I can see were I created the confusion my appologies, now that all know the conditions in which I dive, tropical waters, no currents, and the othet things I already mention, am I still not suited to do a DECO dive under normal circumstances ???
 
I was taught you should have a plan for any two failures. If you have 3 failures of any items then it is just your day to go. So a single tank and one computer won't cut it.
 
Another option, if you haven't already, is to look into Nitrox to help extend your bottom times.

You are right on that, that is another course that I want to take, but then I have to learn if I can go in the 35m range and 40m after doing the Deep diving course and don't get oxigen poisening, there are miles of knowledge that I need to undergo, but that is why I'm asking as well in SB.
 
https://www.shearwater.com/products/swift/

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