Diving after flying

[IndigoBlue]

Here are the NOAA no-flying times, from Table 4.3 NOAA Diving Manual:

USN
Letter
Group ... No-Fly Time

A ... 0:00
B ... 0:00
C ... 0:00
D ... 3:28
E ... 6:54
F ... 9:43
G ... 12:05
H ... 14:09
I ... 15:58
J ... 17:35
K ... 19:03
L ... 20:23
M ... 21:37
N ... 22:46
O ... 23:49
Z ... 24:00

So if you are asking about pushing the limits, this chart is a good notion of where the limits are.

So what of the hubbub of 12 hrs, 18 hrs, or 24 hrs?

Per the NOAA chart, 12 hrs works for a USN F diver, and 18 hours works for a USN J diver, and 24 hrs works for any NDL diver.

A USN F diver would generally be anyone who did a single dive deeper than 80 ft, or two dives deeper than 35 ft. Since that applies to most NDL resort diving, then the 12 hour limit is feasible, but also is cutting it close, per the NOAA chart.

A USN J diver would generally be anyone who did three or more dives within a day deeper than 50 ft. Since that applies to a fair amount of morning-and-afternoon NDL resort diving, then the 18 hour limit is more appropriate for that type of two-trip-a-day diving.

My personal opinion is that 12 hours is not long enough, but you might be ok with it, if you stay well hydrated; and that 18 hours is minimal, with 24 hours being your best bet. As for DAN, since they are also in the publication business, like Rodales, they need to paint with a very broad brush. That is where DAN's 18 to 24 hour recommendation probably comes from.

The organized dive trips that I have been on normally institute a 24 hr waiting period both BEFORE flying and AFTER flying. In other words, there will be no scheduled scuba events during the day of your arrival. And your last day at the resort will normally be a no diving day, during which you go horseback riding, or go on boat rides, or kayak, or freedive, or just swim or lie out by the pool and feed your face.

 

[Spectre]

Mmh... As far as I know, the cabin of a normal commercial plane is pressurised to a pressure resembling an altitude of something like 2300m. So even without the unlikely event of a loss of pressure, it's not a good idea to "ascend" to that altitude within minutes shortly after diving.

Yea, the 2300m sounds about right. I've heard 8000 feet.

However I see detailed reasons, but not really the simple generic reason....

The tables and computers you dive with are designed for use at sea level, and are designed to bring you back to sea level without getting bent. Special calculations and adjustments need to be made, and acclimation periods too, for adjusting the tables for use at higher altitudes [an Altitude Diving class will teach you the specifics]. If a plane is pressurized to 8000 feet, then the table design of returning you to sea level doesn't apply anymore. Likewise since you aren't acclimated to 8000, it's not like you can set your computer to use a conservative altitude setting and set it to something like 10,000 feet.

 

[Scubakevdm]

Sometimes I get on a plane while I'm diving.

 

[Kim]

When we go to Okinawa to dive the diveshop pickup meets us at the airport and takes us straight to the boat. However the flight is only an hour and a half so there are no problems with dehydration/tiredness etc. I have never experienced any problems and this is a fairly standard practice in Japan as people tend to live on very tight schedules (I know one couple who went to Europe for their honeymoon - they were there for two days! one day in England & one day in France - then they came back!!)

 

[IndigoBlue]

Sometimes I get on a plane while I'm diving.

Tortugas??

 

[Scubakevdm]

Tortugas??

Yes, please!

 

[Sideband]

I'm only tossing in my 2 cents worth here because there were a lot of good explanations about flying after a dive I didn't see any real explanation of diving after flying.
Before your flight your body has reached a point of equilibrium in regards to the Nitrogen in your system. When you are on the plane you will experience a slight pressure drop as it is pressurized to approx. the equivilant of 8000 feet.. During that time you will start to out-gass Nitrogen from your system because you are at a lower pressure than normal, so, when you land you will actually have a bit less Nitrogen than someone that lives where you landed (though the amount is very small). As you walk around and get geared up you are ever so slightly on-gassing to get back to equilibrium and it doesn't matter if you do that on land or in the water. Since problematic bubbles form when you have excess Nitrogen in your system for the altitude you are at and not when you have less, there is no problem diving after flying.
If anyone sees any corrections that need to be made, please make them. Hopefully I didn't just confuse you, but if so feel free to ask questions. This is how it was explained to me when I asked.
Joe

 

[voop]

well, my only concirn with diving after flying is to off-gas those complimentary in-flight champagnes prior to on-gassing nitrogen

As for flying after diving...I try to rule-of-thumb 24h. Not as much to off-gas as to get a chance to explore a bit of the shore prior to returning. If I need to fly shortly (<24h) after surfacing, I do calculate a dive and deco profile corresponding to my departure. Others have given good examples as to how such can be calculated.

 

[Rick Murchison]

Here are the NOAA no-flying times, from Table 4.3 NOAA Diving Manual:

Please note that this is just a piece of the NOAA table - the 8000 Feet MSL table (typical cabin altitude for commercial airliners). If you are flying in an unpressurized aircraft or driving over a pass higher than 8000 feet MSL then you need to consult the whole table.
Rick

 

[eamonhan]

Hi everyone,

I am trying to find out how long to wait after flying before I can dive. I am getting conflicting information and there is not much on the net!