19 replies to this topic

[densha99]

I am working my way toward training myself for wreck diving. In doing so, I am interested in training for Staged Decompression and Advanced Nitrox. I was wondering if anyone else was interested in the same kind of training.
This line of training might not just be for people looking for more "tech" diving training. I believe it would be applicable for anyone looking to really understand more about how gas management works, have a deeper understanding of Enriched Oxygen diving as well as just understanding more about decompression in general and the planning of decompression diving.

I believe on a recent trip we had a couple of people whose computers told them they had gone beyond their no stop diving limits and slipped into a decompression scenario. This class would be an eye opener I am sure (yes, you could argue that they may have had very conservative computers compared to everyone else). But if you were diving and you had such a thing happen, you would be much more informed.

As a diver, the more I truely understand about how this all actually works, the better diver I am. So my approach starts here.

If you would be interested in such a thing, throw a note up. You can also PM me if you want and I can scout around to see what is out there. Either way, it's all good.

All input welcome!

[drdiver]

I have some interest in learning more on this subject. I'm a little old for decompression, but with proper attention I think I could do it safely.

[fun2dive]

Does age have any effect on decompression? (I only think of compression - of your disks!)

[scubafanatic]

...additional points to ponder:

If this 'interest' is in response to the SD.com's NC wreck trips, perhaps we could begin by 'someone' ( WW ? ) doing a 'recon' and touch base with the proposed dive charters to be hired for the trips ?

We need specifics on each boats requirements/standards...will they permit a rec/tech 'mix' or do the trips have to be 100% technical or recreational ?

Do we need to build a specific package of chosen ships to dive, to tailor the dive sites to best fit the group's level of expertise ? ( ie depth ranges/ gas mixes/ tank configurrations/capacities/ training 'certs'/experience )

What level of logistical support will be available......singles ? doubles ? gases ?

What environmental conditions can be expected ( waters temps/ visibility / currents )

...not much point is getting too excited or too involved in advanced training if the group is disqualified from the get-go........or worry about cramming in some quickie training that may be overkill for a SD.com group trip.

...outside of a specific SD.com interest though, I'd agree any adiditional training is a positive step.

Karl

[maninthesea]

Does age have any effect on decompression? (I only think of compression - of your disks!)

Yes
Anything that affects your circulitory system affects decomprssion. Age, injuries, dehydration, fatigue, physical fitness, obisity, work load, not being able to spell!
There are other predispositioning factors that increase risk to DCS but most are related to circulitory system.

Jim

[Genesis]

Yep.

On the other hand, most software and computers are pretty conservative. They kinda have to be - since most of America is overweight, under-exercised, etc.

All tables have some risk of DCS built into them. The question is 'what is acceptable?' The Navy's "exceptional exposure" tables carry a five percent (!) risk of a hit - but that's considered "ok" when the mission is blowing up some bridge or ship that otherwise kills everyone. Of course if you dive for fun then a 5% risk isn't good at all

If you want to see 'radical' decompression strategies, read about some of the "ideas" that folks like George Irvine propound upon. Intetionally bubbling into the venous circulation and such. The problem of course is that if you try something like that you're a guinea pig and if you're not up to the task physiologically you're going to regret it. IMHO - don't try that nonsense at home. There was a lady who killed herself playing that game over at Little River about a year ago - she thought she'd climb up the steps after a nice deco cave dive without sufficient washout first, nucleated herself a nice bubble load, and collapsed - by the time the EMTs got to her it was nighty-night time.

Helium in your gas is both a blessing and a curse. A blessing as it diffuses about 4x as fast as nitrogen - which means its more predictable, and thus, "done right" it can be safer. Not to mention that you can think rather than being narced out of your mind; seeing a "beast" in the wreck or cave is probably not so good for your thought processes and rational execution of your dive plan! A curse in that screw-ups are more likely to paralyze or kill, instead of just hurt, because that faster diffusion means that if you "punch out" you're going to take a bubble load all at once, rather than more slowly.

I've never understood why people have such an urge to cut down their runtimes. What's wrong with a few more minutes in the water? I make a practice on cave dives to sit in the water breathing my O2 bottle for an extra few minutes after I surface - its not gonna hurt you, and it might be that extra off-gassing that keeps you from getting screwed one day.

Edited by Genesis, 25 January 2005 - 08:21 AM.

[WreckWench]

...additional points to ponder:

If this 'interest' is in response to the SD.com's NC wreck trips, perhaps we could begin by 'someone' ( WW ? ) doing a 'recon' and touch base with the proposed dive charters to be hired for the trips ?

We need specifics on each boats requirements/standards...will they permit a rec/tech 'mix' or do the trips have to be 100% technical or recreational ?

Do we need to build a specific package of chosen ships to dive, to tailor the dive sites to best fit the group's level of expertise ? ( ie depth ranges/ gas mixes/ tank configurrations/capacities/ training 'certs'/experience )

What level of logistical support will be available......singles ? doubles ? gases ?

What environmental conditions can be expected ( waters temps/ visibility / currents )

...not much point is getting too excited or too involved in advanced training if the group is disqualified from the get-go........or worry about cramming in some quickie training that may be overkill for a SD.com group trip.

...outside of a specific SD.com interest though, I'd agree any adiditional training is a positive step.

Karl

Not sure if I should address this fully here or in the wreck vs cave diving thread or to just start a thread on NC diving specifically. (If this thread deviates from the discussion of staged decompression and advanced nitrox then I'll move it.)

However to answer your questions...I have been doing recon for over 10 years with the NC operator that I use so I can respond to all the questions you raise.

In a nutshell....the depths average 80-120 feet with opportunities to go to 130 on certain wrecks. You will generally run out of bottom time before you run out of gas when diving air and in many cases...on nitrox before you run out of gas as well. We do dive steel 100's as the standard bottle size and the standard gas mix is 30%.

Most of the wrecks are scattered wrecks with minimal opportunities for penetration. Most penetration is difficult to find so repetitive dives on certain wrecks is almost necessary to even be in the correct location for the few penetration opportunities that do exist. The notable exception is the U-352 German U-Boat and in that case special permission to penetrate must be obtained from the charter coordinator who acts on behalf of the boat captain. Numerous reasons exist for this and they can be discussed offline if you desire to penetrate this particular wreck.

Line skills are very valuable for exploring off the wreck as well as keeping orientation in the event of compromised vis. Many of these wrecks have been cable layered and the debris field stretches for quite some area making natural nav all but impossible. However, it is often these wrecks that yeild the highest artifact recovery such as a floor tile, a bullet, some small brass object, etc.

As for combining rec and tec....we do it all the time. However our tec divers do not do 'one long dive'...rather they do two longer yet more challenging tec dives working to a maximum run time and figuring mixes and offgasing from that. Stage bottles can obtain proper mixes if certified to dive those mixes and if the tec divers are in first and out last they have a minimum of 2 hours and then a minimum of 2 hr surface interval to work with between the second dive of the day. Unlike other operators, we do not have an afternoon charter nor are we rushed to return to shore, so we take most of the day to enjoy our dives the sun and catered lunch at sea which is part of the dive pkg.

Without addressing all your questions in this thread, I will address them in a thread specifically on NC wreckdiving which I will link back to this thread for those interested, all the wrecks in NC can be done from a recreational standpoint and that is how most dive them or from a more tec standpoint which for the most part means longer bottom time and not deeper depths or penetration. In order to obtain longer bottom time, a diver needs to first consider using nitrox. For many that will be more then sufficient. However for some that will still only be the icing on the cake and they will desire more. For the latter group doing some casual deco of 5-10 minutes will pretty much match up air consumption to maximum bottom time...however once you consider doing deco as part of your dive you owe yourself and those around you the proper training to ensure you can calculate your gas consumption rates properly, how to offgas faster with a different mix, how to use and sling a stage bottle correctly, etc. Finding yourself in the situation where you have an unplanned 5 minute deco obligation is one thing...planning your dive to include 5-10 minutes of deco on every dive requires that you know what you are doing and therefore should take additional classes. The course(s) densha99 is looking to take are exactly what he needs to take.

Hey SF...have you taken them? If not you might want to join Densha99 when he takes his.

[Genesis]

IMHO unplanned deco obligations (of any length) are extremely uncool. While emergencies do arise, that's not the type of "unplanned" that I'm referring to.

This is one of the things that drives me batty about some of the charters. They give people grief about slinging a deco bottle, but then those same folks stay a bit longer and deco out on backgas, and to "hide" it perhaps even just come up to "safety stop" depth and make an "extra long" one rather than doing a proper profile ascent.......

I can see subs being a special case on penetration - they're very tight internally. I've not yet dove one, but I've walked through a few from that era on display, and I'd expect they'd offer plenty of real no-bs hazards for the unwary..... especially considering that they're real wrecks and are there in almost every case due to battle damage.

[texasmermaid]

At the risk of contributing something on topic to this thread , mark me down as interested in some training on Staged Decompression and Advanced Nitrox. It would be great information to understand even if I don't go down that road with my diving. Keep me up to date on when and where. Thx!

[WreckWench]

IMHO unplanned deco obligations (of any length) are extremely uncool. While emergencies do arise, that's not the type of "unplanned" that I'm referring to.

This is one of the things that drives me batty about some of the charters. They give people grief about slinging a deco bottle, but then those same folks stay a bit longer and deco out on backgas, and to "hide" it perhaps even just come up to "safety stop" depth and make an "extra long" one rather than doing a proper profile ascent.......

I can see subs being a special case on penetration - they're very tight internally. I've not yet dove one, but I've walked through a few from that era on display, and I'd expect they'd offer plenty of real no-bs hazards for the unwary..... especially considering that they're real wrecks and are there in almost every case due to battle damage.

Genesis you are exactly right! It is NOT cool to do planned unprepared deco...aka deco that you are not qualified to do or do not have the appropriate training to do. However once you have the training...you should as you suggest practice the skills in a safe environment until they are second nature.

And you are right...most dive charter ops fear that if you have the tools to do deco that you will...of course you also have a number of highly unqualified people who have the tools aka stage bottles etc. and most certainly do NOT know how to use them! -ww

[scubafanatic]

Hello WW and texasmermaid,

WW, I'll answer your last question first.........yes, I got my Advanced Nitrox/Deco Procedures cert 2 years ago.......trained at the Blue Hole (Santa Rosa, NM), the water was a bone-dhilling 58 degrees, used twin LP steel 95's, along with an AL40 100% O2 stage bottle...it was quite a shock how much all that gear weighted...WHEW !!!

...also did a week of cave class in Akumal, Mexico....dove manifolded AL80's only, no Nitrox or stages, due to the shallowness of the Mexican cave systems.......and while it was a TON of work shlepping all the gear (my gear weighed over 120 lbs ! ) through the jungle and up and down some substantial , very rugged , rocky terrain, I'll honestly say it was easily the most exotic and educational diving I've ever done!

The cave systems of Akumal defy description...I was sooo totally blown-away by the visibility/grandeur before me.....it was surreal......I cannot imagine there can be any diving experience on earth more magnificant.....a fantastic physical and intellectual challenge...looking back on it it still feels like a dream.....it's as close as a human being can get to visiting an alien world without joining NASA..

...which reminds me WW....have you ever considered sponsoring an Akumal 'cenote' singles trip ? .....there might be enough group interest to launch that...... only BOW cert is required, and would give the participants a nice taste of the awesome experience.

...back to the NC wreck 'angle'......OK, you've got a favored charter lined up, and the wrecks under consideration aren't really major penetration wrecks.....which is fine by me, we'll have our hands full mastering the gas/deco planning as is, no need to task overload with reel work at this time.....and since it's 'vacation', no need to build too much stress into the trip.

I do have a preference for diving manifolded doubles......nothing too massive, say AL80's on such a trip.......I'd assume those are available on request ? My exposure to 'tech' training has increased my safety consciousness......I dive a dual-bladder wing too.....even on kiddie dives.........or perhaps at least a larger capacity single steel double, if not a twinset? ...not trying to be high-maint.....if you don't know just let me know who I need to call at the charter and I'll find out for us.

.......as far as Kevin's class, is SD.com considering organizing such a class.....is a prospective list of candidates being penciled in somewhere......and any thoughts/preferences as to the shop/instructor to be used ? What agency is being considered ?

...I might like to 'redo' my Advan Nitrox/Deco Pro class again anyway...it's been 2 years and I'm pretty rusty........ diving doubles is no biggie but I need a refresher on the gas management aspect.

....hey, texasmermaid...........welcome to " THE DARK SIDE "

Karl

[Diverbrian]

IMHO unplanned deco obligations (of any length) are extremely uncool.  While emergencies do arise, that's not the type of "unplanned" that I'm referring to.

This is one of the things that drives me batty about some of the charters.  They give people grief about slinging a deco bottle, but then those same folks stay a bit longer and deco out on backgas, and to "hide" it perhaps even just come up to "safety stop" depth and make an "extra long" one rather than doing a proper profile ascent.......

I can see subs being a special case on penetration - they're very tight internally.  I've not yet dove one, but I've walked through a few from that era on display, and I'd expect they'd offer plenty of real no-bs hazards for the unwary..... especially considering that they're real wrecks and are there in almost every case due to battle damage.

Genesis you are exactly right! It is NOT cool to do planned unprepared deco...aka deco that you are not qualified to do or do not have the appropriate training to do. However once you have the training...you should as you suggest practice the skills in a safe environment until they are second nature.

And you are right...most dive charter ops fear that if you have the tools to do deco that you will...of course you also have a number of highly unqualified people who have the tools aka stage bottles etc. and most certainly do NOT know how to use them! -ww

This is why I nicely explain to captains that the the bottle of EAN50 that I am slinging is for my ascent to shorten my surface interval. They LOVE that explanation . Of course, if I plan to do deco and it is approved, I tell them that as well. I have never had a charter captain give me grief about it yet. If you recall, I had a deco bottle on both dives we did on the Keystorm in Brockville. Up here, it goes with me and gets used on any dive below 100 ft. as a safety margin.

Even the modern subs are tight. I would have NO intention of trying to go inside of one in tech gear. The ones that I worked on for three years were tight enough in places just wearing the issue submariner's jumpsuit and tennis shoes.

[Diverbrian]

At the risk of contributing something on topic to this thread , mark me down as interested in some training on Staged Decompression and Advanced Nitrox. It would be great information to understand even if I don't go down that road with my diving. Keep me up to date on when and where. Thx!

I had that attitude when I took my Adv. Nitrox as well. Now, I almost do more dives with EAN50 as a deco gas and light deco than I do recreational dives. I consider a properly planned and executed staged deco dive safer than "riding the computer" that I see so many divers try to do.

Enjoy your course!

[WreckWench]

Well this thread is doomed to be convuluted...sorry gang....at least one point is on topic! LOL!!!

  ...also did a week of cave class in Akumal, Mexico....  I'll honestly say it was easily the most exotic and educational diving I've ever done! 

Agree...several of us extended the Cozy trip to scoot over to Akumal and it was awesome!

...which reminds me WW....have you ever considered sponsoring an Akumal 'cenote' singles trip ?  .....there might be enough group interest to launch that...... only BOW cert is required, and would give the participants a nice taste of the awesome experience.

Yep...have thought about it and will look at doing it down the road...might even combine it with the cavern certification if enough people are interested.

    ...back to the NC wreck 'angle'......OK, you've got a favored charter lined up, and the wrecks under consideration aren't really major penetration wrecks.....which is fine by me, we'll have our hands full mastering the gas/deco planning as is, no need to task overload with reel work at this time.....and since it's 'vacation', no need to build too much stress into the trip.

You got it...btw...to say I have a favored charter lined up is a bit of an understatement...I've dove with this boat capt for 12 years and have been adopted into the 'family'!!

    I do have a preference for diving manifolded doubles......nothing too massive, say AL80's on such a trip.......I'd assume those are available on request ?  My exposure to 'tech' training has increased my safety consciousness......I dive a dual-bladder wing too.....even on kiddie dives.........or perhaps at least a larger capacity single steel double, if not a twinset?  ...not trying to be high-maint.....if you don't know just let me know who I need to call at the charter and I'll find out for us.

Doubles are allowed however due to space considerations without paying extra... the boat can accommodate one set of doubles per diver however that set needs to accommodate both of your dives. We can have a number of single bottle backfill tanks to top off with or to use for your second dive. Arrangements for these are made with me for each trip on a first come first served basis. Doubles are not available for rent...you'll need to bring your own bands and manifolds...only the bottles are available.

  .......as far as Kevin's class, is SD.com considering organizing such a class.....is a prospective list of candidates being penciled in somewhere......and any thoughts/preferences as to the shop/instructor to be used ?  What agency is being considered ?

I think Kevin is merely looking to see who might be knowledgeable about these classes as well as who might like to participate with him. I'd presume he'd take the classes from Ron Carlo under TDI...at least that would be my suggestion.

    ...I might like to 'redo' my Advan Nitrox/Deco Pro class again anyway...it's been 2 years and I'm pretty rusty........ diving doubles is no biggie but I need a refresher on the gas management aspect.

I'm sure Kevin would love to have a fellow SD'er along.

[Genesis]

I have no problem with that on the dubs - depending on the expected profiles I will bring either double 72s or double HP100s, and a sling tank (AL40) of EANx50.

That 50/50 tank is cheap to fill; I pay $16 for a "T" cylinder of O2, which has roughly 300cf in it..... so that 40cf bottle costs me a couple of bucks to reload, and one will easily handle two moderate-deco dives, or an entire weekend of light deco/no-stop diving.