18hr Flight Ban Valid After 5' Dive?

[Blackwood]

To fully saturate at any depth and then ascend to altitude without decompressing would end badly. Your comment above about being fully saturated at 5 fsw (which is possible but not probable unless someone wanted to live at 5 fsw) and then being OK to fly was stupid. You claim to be helping someone who is obviously new and doesn't understand, or he wouldn't have asked, but then claim to have answered with a joke only after being called out for it.

I suggest pulling out a calculator and doing the math.

Tissues at 5FSW saturate at what, 17PSI give or take? Ambient at 8000 feet AGL is about 11PSI? That's a reasonable pressure gradient on most every decompression model.



I'm not going to touch the "live at 5 fsw" comment other than to say that 98% (6 time cycles) is 98% no matter how deep you are.

 

[mempilot]

5FSW saturates at what, 17PSI give or take? Ambient at 8000 feet AGL is about 11PSI? That's a reasonable pressure gradient on most every decompression model.

Totally agree with you that flying after saturation at 5 fsw is not stupid.

BTW, 8000 feet is in reference to cabin pressure and not AGL. Cabin pressure is not equal to aircraft altitude or outside ambient pressure in a pressurized aircraft. Unpressurize the airplane and the pressure gradient will grow quite quickly.

 

[Blackwood]

Totally agree with you.

Maybe I missed what you and Thal are bickering about.

He is saying that if you never get deeper than 5 feet, no matter how long you stay, the gradient to a pressurized cabin is within theoretical limits.

BTW, 8000 feet is in reference to cabin pressure and not AGL.

I'm aware of that. I just short-handed "the atmospheric equivalent to which commercial airliners are pressurized"

I definitely agree that a sudden loss of cabin pressure would not be a fun situation.

 

[nwhitney2003]

I'm not really critical of you for telling him to call DAN and ask. Is it overkill? Yes. Why, because it shows absolutely no knowledge of what is going on with your body while diving. Many use DAN as a safety net, and if every diver tied up the great folks at DAN with safety net questions, people trying to get through with real questions that are more severe would never get through.

There is a certain level of knowledge about inert gas loading that every diver should know. Many instructors don't understand it themselves, and therefore, it doesn't get passed on. We see divers come down on vacation dives without the most basic skills or knowledge, yet they possess the C-card from the largest training agency in the world.

This board takes the community of these divers and makes them all instructors by letting them provide bogus information to the masses. Those that don't understand will take the fact that they read such information on SB as gospel, and they will go about their diving with no sense of the truth or comprehension of what they are involved in.

So, I'm sorry if you are offended at my scoff about calling DAN, but the point is that a simple, "Call you instructor and ask him." should be the response to about 75% of the questions answered on SB. If their instructor doesn't know the answer, then the diver should contact the agency they are trained under and get clarification. Leave DAN for complex medical or emergency type questions.

There are almost as many misinformed and poor instructors out there as there are misinformed and poor divers.

I'm not offended, I think you are wrong. If your claim that most instructors don't understand inert gas loading is correct and that there is bogus info here on SB then I ask again, how does a new diver (myself included) sort out the correct and incorrect information? I could call my instructor but according to your claim he most likely doesn't understand inert gas loading. I could choose to follow what you said but maybe your info is bogus? Maybe you're correct and the other guy is wrong. How do I know? I don't believe that calling DAN with this question is a bad idea. Nor do I believe it not a "real question", not sure what you mean by that.

This is taken from DAN's website:
"DAN, a nonprofit organization, exists to provide expert information and advice for the benefit of the diving public".

"Additionally, DAN operates a diving medical information line, conducts vital diving medical research, and develops and provides a number of educational programs for everyone from beginning divers to medical professionals".

So, who would I trust, DAN or people posting information that may or may not be correct, info that I may not be able to verify, backgrounds of people I may not be able to verify. Is calling DAN overkill? Maybe if you talked to everyone at your certifying agency, every LDS within a 10 mile radius and their instructors.

I do agree with you that contacting your agency is also a good idea.
Who would have more up to date data regarding scuba? I don't know the answer to this one but I'd bet people posting on here come in dead last.

I can't speak for the folks at DAN but as a former lifeguard, I would rather someone ask me a "safety net" question and for me to provide correct info. then for me to make a rescue and to endanger my life because they had either incorrect info or didn't bother to ask.

DAN is in the "business" of emergency treatment/information and equally important educational programs and publications.

I'm not advocating every diver to call DAN with any question or concern, but they shouldn't feel that they can only call except in an emergency.

 

[TSandM]

If an airliner depressurizes at 30,000 feet, it isn't going to matter much whether you dove before it happened or not -- you're going to be very quickly in a world of hurt.

Honestly, mempilot, do you believe what you are saying? If so, I can recommend some reading material that will hopefully give you a better understanding of the modeling of gas kinetics while diving. If you use the crude, Haldanian approach, you can tolerate a 1.58x gradient without symptoms. 5 feet is about 1.15 ATA. That means you can go up to about .72 ATA (about 8000 feet) IMMEDIATELY after diving without much risk of symptoms. And the gas loading you got, minimal as it was, is going to begin to decay the minute you get out of the water; at 6 hours, all the compartments with half-lives of an hour or less are going to be essentially empty of excess nitrogen. Tissues with half-lives longer than that didn't even load much of the tiny excess nitrogen that was present at 5 feet, so they probably would have tolerated lower ambients immediately.

It takes significantly deeper depths and significantly longer exposures to load the slow compartments enough to be in trouble when flying. It's a bigger issue for people who are doing mutiple dive/multiple day trips, where, over a week, you can amass some significant loading.

The OP is probably at higher risk of getting injured in an airplane crash by flying than he is of getting DCS.

 

[mempilot]

10 fsw = 1.3 ATA

PN2 @ 10 fsw = .78 * 1.3 = 1.02 ATM

A Slow Tissue Compartment with 40 minute half-life:

HTP1 40 min 50%
HTP2 80 min 75%
HTP3 120 min 87.5%
HTP4 160 min 93.8%
HTP5 200 min 96.9%
HTP6 240 min 98.4%

HTP6 = fully saturated

((Y-X)/2)+X); where X = HTPn half life % and Y = HTPn+1 half life %

My point about living at 5 fsw is summed up above with an example at equivilent maximum depth of the pool in seawater. It would take the diver 240 minutes or 4 hours breathing air to become fully saturated.

I doubt he stayed at 10 feet for 4 hours.

 

[mempilot]

Honestly, mempilot, do you believe what you are saying?

What? That he can fly after completing a training dive in a 10 foot pool? Absolutely. Unequivically. Please tell me you don't believe he can fly after a couple of hours in a 10 foot pool.

 

[mempilot]

People. Please go back and read my comments carefully. Please don't put words in my mouth. I absolutely believe he can fly after a pool session. I never stated otherwise. My comments about flying after diving in a pool were about someones comments about saturation, and my point was that it takes many hours to saturate at 5 fsw.

There seems to be a serious lack of careful reading going on. A few of you are very quick to open your mouths before you open your eyes. Please read every word and sentence. Comprehend first, then type.

 

[DandyDon]

Sorry, I'm late to the party...

Actually, aerobic exercise increases the risk of DCS. Take a nap, you'll probably be tired after your pool session.

If you're going to interject facts that have nothing to do with the discussion, wouldn't it be good to include that tidbit? There's no way DCS can be involved in a flight after diving to 10 ft. BTW, Dr.Deco has gone on record as discouraging naps soon after diving as exercise can speed up off gassing too much but napping can retard it - neither of which has anything to do with a 10 ft dive.

Other than that, I'll just echo what deco_martini said. Assuming you're not planning on taking a red-eye flight on Wed night, you'll be fine.

Just try to dry your hair or proect it from wind at the airport so you won't get a chill.

That's like running to the ER because you think you might be in danger of getting a splinter.

Oh when in doubt, call DAN. I wouldn't bother here, but other times sure..

Prior to a dive ? ... does a half hour session on the treadmill/elliptical an hour or two before a dive put me at greater risk? or is it only After a dive?

That one I don't remember. I'd have to search Dr Deco forum.

Not to belittle the original poster, since they are a new diver. Go fly without worries.

To the rest of you suggesting calling DAN for guidance, or bringing up aerobic exercise contributing to DCI after a pool dive, or being saturated at 5 ffw: ARE YOU KIDDING ME????? Please stop diving. You obviously have no grasp of the sport you are involved in.

Whatever flavor Kool-Aid you've drank, it must have been really good and you went back for seconds.

Were you ever new?

I wasn't so concerned with him exercising after a pool dive but exercising after doing real dives in real locations. I've seen people in DM classes think it was okay to go play flag football after a full weekend of diving.

Better said.

Please you have been here long enough to know we get work up the colour of fins and wet suits.....

Is there a good paint for fins?

Personal opinion.... If you have never called DAN, you need to dive more... in most cases.

The only time I have called DAN was when a less experience buddy follow the DM's advice in HI and dove for 65 minutes at 85 feet with no hang. I called DAN even though she was not a member and they knew that, they called her.

I have nothing but Praise to say about calling DAN. Thankfully I have never had to use the insurance side, so I will not jinks that

I've called them a few times. I once had a buddy leave the dive boat after we'd dived >100 ft on a wreck to snorkel with dolphins while I napped. I later learned that he did some free diving, called them right away; they agreed it was a bad idea and told me what to watch for, then I finished lunch. Called them other times about other things. When in doubt, sure.

No, you don't have to be a member to talk to them on any line - but it's a good idea.

 

[mempilot]

If your claim that most instructors don't understand inert gas loading is correct and that there is bogus info here on SB then I ask again, how does a new diver (myself included) sort out the correct and incorrect information?

Most instructors have been taught a basic level of knowledge of gas loading. Instructors who teach technical level courses, as well as some recreational instructors, have a higher understanding of tissue loading and offgassing.

Many of the rules; ie. 12, 18, 24 hours dive to fly time are guidelines set at very high limits. NOAA advocates another set of rules that actually look at ending pressure groups and actual cabin pressure altitudes for ascent to altitude after diving. The point I tried to make earlier, is that people know the rules they were taught, but they don't neccessarily understand the real data behind it.

You will get all kinds of "The sky is falling." type of guidance from the vast majority of divers. I'll tell you that your instructor and their agency should be your first avenue for furthering your knowledge of something you don't understand. Trying to learn it on the web can be garbage in, garbage out.

If you don't learn what you need to know from your instructor, might I suggest moving on to another level of diving where the specifics are taught to every student.

DAN is a tool, and I'd encourage you to call them when needed. But don't use them as a replacement for good training. A good instructor who teaches for an agency that puts this knowledge in their hands is the proper starting point.

DAN is in the "business" of emergency treatment/information and equally important educational programs and publications.

I'm not advocating every diver to call DAN with any question or concern, but they shouldn't feel that they can only call except in an emergency.

You are absolutely right with these two statements. Read as much literature as you can on a subject. SB is not literature. Then call them if you need clarification.

But the question being asked, while obviously not easy to the original poster, should have had a very simple answer:

Yes, you can fly after a pool dive as long as you didn't live at 10 feet.

Calling DAN to get that answer would have been a waste of good resource and was actually something SB could have answered without the complications of people throwing all kinds of whacked out references to confuse the poster.

I'm sorry if you felt I jumped on you personally. I didn't mean to attack you. I keep that DAN number handy, as I've had to use it in the past to ask about baratrauma to an ear while on vacation once. They were invaluable to me, as they are to others.