Flying after Diving

[spthomas]

This question has come up often, and now I'm looking at it. The typical scenario is this: I want to dive somewhere nice, warm, and blue. I can do this, but I only have a weekend (say Friday afternoon to Sunday evening). To go, I have to fly. So get there Friday afternoon, dive Saturday all day (2-3 dives). Flight leaves Sunday afternoon. What about diving Sunday morning? Hate to waste a perfectly good diving day, but this means getting on a plan within 2-3 hours after diving.

What are people doing about this? I know it comes up a lot, but I only thought to ask about it when it affects me personally (selfish that I am). I've always told other folks that ask "no, you must wait 24 hours to fly". But is that still true? And is this really a relevant risk?

I want to go somewhere next weekend, but everywhere from Texas is a flight to get to blue water.

=Steve=

 

[gkndivebum]

Here's a link to DAN's Flying after Diving FAQ

Oddly enough this is relevant to where I live -- there are some pretty dramatic
elevation changes on the Big Island...

 

[DandyDon]

I know. I just have to take longer weekends. 4, 5, 6 day weekends are good.

The NOAA Dive Manual, available from Amazon for around $80 I think, can give you some guidelines on shallow dives only a few hours before flying, and Nitrox 36% will give you even shallower Adjust Depths.

I would not try it without that book!

BTW, if you screw up and start to get symptoms on the plane, don't bluff. Tell the FA, ask for O2, and expect DAN to pay for your ambulence ride when the plane lands.

 

[DENNISDIVES]

Dive smart not stupid----wait 24 hours---it's an easy answer !!!!

 

[DandyDon]

Dive smart not stupid----wait 24 hours---it's an easy answer !!!!

Okay, Dennis - you're an Instructor, so you have to give the extra conservative advice. But if you look at the original thread starter's Profile, you'll see that Steve is an SSI/DiveCon himself, as well as a medical professional. Ergo, both of you guys are certainly more qualified than I am!

Let me tell you how I would look at a possibility based on NOAA Dive Charts and Flying After Diving Chart...

(1) At 7:30am the last full day in Key Largo, I dive the S.Grove to 110 feet on 32% Nx for 25 minutes = G Group.

(2) I take a 1:16 hour SI = E Group.

(3) At 9:11am , I go down on the Grove again to 90 feet with 36% Nx for 24 minutes = J Group.

(4) I take 3:05 hour SI = D Group.

(5) At 12:40pm, I use 36 Nx to go to 70 feet for 41 minutes = I Group.

(6) I take a 1:20 hour SI = G Group.

(7) At 2:41pm, I use 36% Nx to go to 50 geet for 60 minutes = J Group.

(8) At 7:30 am the next morning, I use 36% Nx to go to 50 feet for 60 minutes = F Group.

(9) After 1:30 hour SI = D Group.

(10) At 10 am, I use 36% Nx to go to 40 feet for 50 minutes = F Group. I'm finished by 10:50am.

At 9pm, after 10:10 hour SI, I review the diving for the last 24 hours - seeing that none of the diving I did the day before affects the flight decision, and see that the highest Group was F, and I need 9:43 hours before getting on the plane.

I'm fine, if I can find a plane that late.

 

[pasley]

I am not an expert and certainly relatively new to the diving game. But, I have taken a chamber ride. Fortunately, I only suffered from tingling feet for a couple of years after. The odds are that you can do it will no ill effects. But then again, maybe not.

But not all DCI is fully resolved with treatment. Some cases result in permanent paralysis, including wearing a diaper for life and living in a wheel chair, or worse, death.

Will that happen to you? Probably not. But the whole DCI thing is not an exact science and there is no one who can say for certain one way or the other. The cost is IMHO not worth it.

The current standard of 24 hours is tougher than it was a few years ago. Ask yourself why? Because experience showed an increased risk to flying in less time. You sound like you have a good plan. But there is more risk to it than if you did not dive the day of the flight. I also do not agree that the previous days dives do not factor into the equitation. You must also factor into the equation dehydration as flying is very dehydrating.

Note, I have personal experience that 1,400 feet can triger DCI.

But, you do what is right for you. For me. I will error on the side of caution.

 

[mempilot]

Dive smart not stupid----wait 24 hours---it's an easy answer !!!!

This is a legal/insurance underwriter answer to the question and is not based on any scientific data.

This is the table I use. I dive and fly every week. I'm in the air or underwater every day. I've not felt any ill effect from using this data, even after consecutive dives and decompression diving.

Added note: A commercial aircraft maintains a cabin pressure altitude of 8000 or less, depending on it's cruising altitude. Sudden loss of cabin pressure is extremely rare and DCI would be the least of your worries as you would more than likely die from a loss of control and impact. A more likely scenario would be a slow loss of pressure which is identifiable and manageable, inwhich case the aircraft would be flown in a rapid descent down to 10,000' or lower. The rate of descent is maintained at a higher rate than the cabin pressure's rate of ascent. Minimal risk of DCI and still very rare.

I plan my ascents to altitude from sea level to 8000'. On shorter flights, we often only reach a CA of 5000'. Maybe the NOAA should do a study using us pilots who dive and fly for a living as proof of their model.

 

[spthomas]

Great discussion all. I know the thinking on this changes over time, and that sometimes good sources of information aren't where you think they are, which is why I asked. (well, maybe hoping that there was cutting edge research I wasn't aware of that'd let me dive on a 3 day weekend!).

But, my advice to everyone is to do the math, and be conservative. As Melvin points out, and many folks don't remember, is that DCS is not a WATER thing. it's a PRESSURE thing. And you can get hit out of the water, like in a plane.

BTW, I've found that Scubaboard is absolutely the BEST way to keep up on the latest in diving. I can't read all the journals and articles and research, or even know where they are. But someone here will, and will share it with us.

=Steve=

 

[DandyDon]

I knew I had this somewhere...

Here at Los Alamos National Laboratory, we have developed a set of altitude diving protocols that are now also sanctioned and adopted by the USN. Excursions in which the change in altitude (not altitude itself) are less than 2000 ft have little risk for air no-deco diving with waits of an hour or two. And going from 5000 ft to 7000 ft after a single dive plays like going from sea level to 2000 ft and is safer. Deco and multiple dives are also covered. All very safe.

Procedures are published in book called High Altitude Diving
from Best Publishing Company (Flagstaff) if you are
interested and parallels NOAA, Cross, NAUI, etc.

Pretty straight forward stuff using standard groups and
not rocket science. Plus info on gauge corrections,
air consumption corrections, buoyancy corrections at altitude.

Bruce Wienke
C & C Dive Team Ldr

Still need to order that book...!