Any divers on the board?

tdager

tdager

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LittleIronPilot
My wife and I are getting SCUBA certified (OW) next month.

She is excited and I am as well. I plan on paying attention to the diving/flying charts as she now is looking forward to using the plane to fly to Florida or the Bahamas to go diving.

Anyone mix diving and flying? Any advice/precautions?
 
I'm a diver too, but haven't flown to a diving location before just because I didn't want to deal with what if.....

I've drivin from Southeastern PA to the Outer Banks and dove off the eastern seaboard to a sunken German U-boat but again drove and didn't fly.

Please Please respect the time tables for rest before flying; no need to be in a hurry.

It'll be a blast and best wishes on ya'll upcoming dives.
 
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Calling Scott Migaldi! (Scott's a dive instructor, among his many other talents.)

I "dive" too (as in I have a certificate), but have never really "mixed" the two.

The March 2007 issue of Dive Training magazine had an article "Worlds Apart: How Aviators and Aquanauts Handle Decompression Illness" by Alex Baylske. That's the issue with the PT-6 on the cover, something you don't often see in a Dive magazine! :)
 
Grant...I will go find that issue!

As far as precautions...trust me I will NOT fly in any sort of proximity to my last dive. I love flying too much to screw myself up, and I know I will enjoy diving as well.

I shall respect the tables!
 
I am a current PADI Master Instructor who has issued well over 400 certifications. I teach every specialty EXCEPT Cavern, rebreather, ice diver, and videographer. I hold several technical specialties but no longer do that type of diving, mostly due to lack of currency.

Flying or going to altitude after diving is a wonderful topic that can get a lot of emotive responses. The answer is that that CURRENT theory is:


  • For a single no-decompression dive, a minimum preflight surface interval of 12 hours is suggested.
  • For multiple dives per day or multiple days of diving, a minimum preflight surface interval of 18 hours is suggested.
  • For dives requiring decompression stops, there is little evidence on which to base a recommendation and a preflight surface interval substantially longer than 18 hours appears prudent.
Source Divers Alert Network
 
I'm a PADI open water instructor, but haven't been diving in a long, long time... I may just get back into it. What the hell, why not... :D
 
tdager said:
I shall respect the tables!
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Dive tables, how retro! ;)

As of 1 Jan 2009 I no longer teach using the dive tables. We now use either the dive computers from day 1 or a dive calculator. The dive calculator has sure made teaching a lot easier. Especially minimum surface intervals. The only place I still teach tables is at the Dive master courses. That course we still cover a lot of topics such as tissue models, m-values, halflife, etc.
 
etsisk said:
I'm a PADI open water instructor, but haven't been diving in a long, long time... I may just get back into it. What the hell, why not... :D
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Are you still a current OWSI? If it has been a few years the structure of the courses and the teaching methodologies have changed dramatically. If it has been a while since you taught you may want to consider auditing a class or two or maybe even and IDC.
 
In answer to the title: "yes".
Decompression and altitude are a real issue. You need 24 hours at the surface to de-gas if you're gonig to go above 8,000 feet, less of an issue if you don't go below 40 feet and do only non-decompression stop dives.

No, Tom there are no dive tables for this situation. The USN doesn't have their closed circuit guys in the tank at Portsmouth then go to 8000 feet MSL....so it's based on NO data.
 
prehistoric tables... lol... me too. I have had a Suunto since day one, but have never flown within 2 days of diving either.

I've just bought a paragliding wing so I may be diverting my scuba FUNds to powered paragliding FUNds for this year but may find a mud hole or two just to keep current for 09.

Oh, and LittleIronPilot, depending on your age, you may find Nitrox a nice alternative to compressed air (AFTER receiving training of course). For me, I end the dive day without being exhausted but it does come with its own limitations too.

Welcome to world of SCUBA.
 
Just as an FYI current off gassing for recreational scuba divers is based on a pressure that is no less than 1000' above MSL. That means that going above that altitude is considered 'flying after diving' and that you should spend appropriate time de-gassing prior to ascending higher than 1000' MSL.
 
smigaldi said:
Just as an FYI current off gassing for recreational scuba divers is based on a pressure that is no less than 1000' above MSL. That means that going above that altitude is considered 'flying after diving' and that you should spend appropriate time de-gassing prior to ascending higher than 1000' MSL.
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That's good to know; I hadn't realized that.

And DAN is a good resource! My instructor had us all enter their number into our phones!
 
gprellwitz said:
That's good to know; I hadn't realized that.

And DAN is a good resource! My instructor had us all enter their number into our phones!
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That little fact is something I impress upon my students, especially those about to go to Hawaii where it is easy to drive from the shore to well over several thousand feet in a short period of time.
 
smigaldi said:
Just as an FYI current off gassing for recreational scuba divers is based on a pressure that is no less than 1000' above MSL. That means that going above that altitude is considered 'flying after diving' and that you should spend appropriate time de-gassing prior to ascending higher than 1000' MSL.
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How does this work for people who dive in lakes, gravel pits, and so on where the ground elevation is higher than 1000 MSL?
 
So it seems what I have heard in the past stands. Do a nice three-four day weekend. Dive on days 1-2 (and 3 if a four day) and make sure I have 24 hours (safety margin) before flying home.

Works for me! :)
 
I've been diving on and off for many years and have started to get serious about it again. The only guidance I could find was to avoid flight above 8000 cabin altitude within 24 hours of any dive and all flight within 18 hours and that seems incredibly oversimplified to me. For instance I expect there'd be a significant difference between flying after reaching the non-decompression limits vs flying after diving no deeper than 30 ft. IOW the amount of dissolved N2 in your blood ought to be a factor in how long to wait. In addition, I think that these times should be adjusted for cabin altitude with more resolution than above/below 8000 (that altitude is typical for an airliner in cruise) as well as ascent rate. I even looked into a few dive computer manuals to see if they offered any variable guidance but every one appeared to go with 24 hrs from the last dive with no adjustment for dissolved N2 or cabin altitude.

Surely a flight topping out at 1500 MSL (e.g. returning from the Keys to mainland Florida) ought to be feasible much sooner than a flight at significantly higher altitude. Heck you could get to 1000 MSL by riding the elevator in a tall building and there's no warnings about that in any dive instruction material I've seen. And speaking of warnings, I've gotta believe that 18 hours after reaching the maximum tolerable dissolved N2 levels, I think you'd be in a world of hurt riding in an airliner that experienced a loss of cabin pressure at FL370.

OTOH I know there is some information about decompression adjustments for diving in water who's surface is significantly higher than sea level, maybe something useful is hidden there. Other than that, it's my expectation that the mechanism of disolved N2 release from blood and tissue is fairly well understood with some decent models (as implemented in a dive computer for repetitive dive duration limits) so it shouldn't be all that difficult to come up with a computer program or nomogram that would predict the safe limits more accurately than a blanket 18 or 24 hour time delay.
 
jmaynard said:
How does this work for people who dive in lakes, gravel pits, and so on where the ground elevation is higher than 1000 MSL?
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Good question. There are special consideration to take into account such as treating your first dive as a repetitive dive if you came up to altitude from below 1000' MSL. You also calculate your pressure groups using something called theoritical depth and you ascend much slower than 60fpm. The special consideration and the additional table of theoritical depth are all covered in a dive course called Alltitude Diver.
 
gismo said:
Other than that, it's my expectation that the mechanism of disolved N2 release from blood and tissue is fairly well understood with some decent models (as implemented in a dive computer for repetitive dive duration limits) so it shouldn't be all that difficult to come up with a computer program or nomogram that would predict the safe limits more accurately than a blanket 18 or 24 hour time delay.
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There are some really interesting things happening with tissues models the last few years. Where most of the decompression tables had been built on the haldean models that were ifrt postulated in the 1890's the newer models are now based on actauly dopplar bubble studies.

The RGBM (Reduced Gradient Bubble model) is becoming a very popular one. There are now several years of empiracal studies that support the theory and at least one dive agency, NAUI, has developed dive tables based on it. Suunto computers is also using it in their dive computers.
 
gismo said:
The only guidance I could find was to avoid flight above 8000 cabin altitude within 24 hours of any dive and all flight within 18 hours and that seems incredibly oversimplified to me.
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See my post above. DAN made the current recommendation in 2002 based on fairly in depth study by them, Duke University and the Underwater Hyperbaric Medicine society.

http://www.diversalertnetwork.org/medical/faq/faq.aspx?faqid=54

Personally I ALWAYS wait at least 24 hours before flying.
 
I am certified (as is my wife), but it has been so long that I would want to have some refresher training before I did any real diving again. That, plus I am in nothing like the physical condition I was in when I was certified...
 
Unless You and Your wife have Navy seal training be sure the aircraft is on the water before starting your dive.:D

Sorry, couldn't resist.
 
gismo said:
... The only guidance I could find was to avoid flight above 8000 cabin altitude within 24 hours of any dive and all flight within 18 hours and that seems incredibly oversimplified to me...
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I think you mean to say to avoid flight up to 8000' cabin altitude. Even a nice ride in a 787 with a lower cabin altitude or a drive over a 1200' pass would be a no-no for 12-24 hours. I always go conservative with 24 hours and 36ish if I've been on a dive boat for a week and I can feel my blood fizz.

This is an important point for private pilots. There is no data that I'm aware of for flights at higher cabin altitudes. So if you're going to go higher than 8000' on your flight home without pressurization, you'll want to wait even longer. All the data assumes commercial flights on airliners.
 
Well i'll add myCongrats on getting certified. I too am a Diver with Advanced open water, Nitrox and Drysuit certs. I haven't mixed flying and diving, and as some people said i don't use dive tables i use a Computer. in either case Be Safe and Enjoy both activities. We don't need to read about any mishaps.
Dave G.
 
I was an instructor but let my cert lapse last year as I wasnt actively teaching since I have a real job now. I sold most of the stuff from my store but I am sorta thinking about getting back into it. I still have my compressor and bank with a "few sets of gear" but I also just got my glider instructor and would enjoy using the heck out of that cert. I have flown to quite a few dive destinations and always invoke a personal 24 hour SIT before flying. Have fun, diving is great!
 
smigaldi said:
Are you still a current OWSI? If it has been a few years the structure of the courses and the teaching methodologies have changed dramatically. If it has been a while since you taught you may want to consider auditing a class or two or maybe even and IDC.
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Nah, I'm not remotely current - wouldn't think of trying to teach, now; I wouldn't even think about trying to dive without a forgotten diver course! Been waaay too long. :eek:
 
cwyckham said:
I think you mean to say to avoid flight up to 8000' cabin altitude. Even a nice ride in a 787 with a lower cabin altitude or a drive over a 1200' pass would be a no-no for 12-24 hours. I always go conservative with 24 hours and 36ish if I've been on a dive boat for a week and I can feel my blood fizz.

This is an important point for private pilots. There is no data that I'm aware of for flights at higher cabin altitudes. So if you're going to go higher than 8000' on your flight home without pressurization, you'll want to wait even longer. All the data assumes commercial flights on airliners.
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No, I meant what I wrote although I was only passing on what I read. And that was "Wait at least 18 hrs before flying on an airliner, 24 for flight in an unpressurized airplane". The 8000 ft limit I mentioned is based on the fact that most airliners limit cabin altitudes to 8000 ft or less. Many stay below 5000 ft most of the time.

And while I have no data (yet) I can't see how a 1200 ft altitude would be an issue several hours after the last dive as the pressure decrease from sea level is only a half PSI, the equivalent to a whopping ONE FOOT of water depth.
 
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