Skydiving After Taking a Cross-Country Flight

[FCipollo 1]

I recently grabbed my A License and know the rule involving not skydiving for 24 hours after scuba diving.

Is there a similar rule for skydiving after taking long flights or vice-versa? I ask because I am traveling to Eloy in December and would like to go skydiving the second I get off the plane.

[AggieDave 6]

The reason for the rule is that if you scuba then skydive you'll get the Bends due to the nitrogen in your blood. Flying is flying is flying, unless you're going to be flying in some sort of highly pressurized vessel with a mixed-gas rig (which you won't), then it won't matter. A commercial jet is pressurized to something like the air pressure at 7,000ft, so it'll be like being in a jump plane (sans the pin checks and farts).

--"When I die, may I be surrounded by scattered chrome and burning gasoline."

[FCipollo 1]

Thanks. Makes sense.

[kelpdiver 2]

Quote

Is there a similar rule for skydiving after taking long flights or vice-versa? I ask because I am traveling to Eloy in December and would like to go skydiving the second I get off the plane.

For that matter, I like to be underwater within an hour or two of landing.

The only way you'll be skydiving 'the second you get off' is if they pick you up!

Has anyone talked with DAN for clarification about skydiving after diving? The 24/12/18/?? WAG is really about flying as a passenger in a jet pressured to 6-8k, with a small risk of losing pressurization. And there's a lot of sentiment that it was lowered to 12 as the general recommendation because dive operators wanted business the day before people flew home.

That's not quite the same thing as going to 15k in an open vessel.

[FCipollo 1]

I was exaggerating with the 'second I get off the plane' comment.

[Martini 0]

DAN's current recommendation is a 12 hour wait after a single no-deco dive and an 18 hour wait after multiple dives whether deco or non-deco. This applies to commercial flights with a cabin pressure of 8000' or better.
I've discussed skydiving applications of this rule with DAN and since there is no research data on skydiving after diving they aren't willing to advise anything more aggressive. Personally I abuse the rule frequently but conservatively.

Sometimes you eat the bear..............

[kelpdiver 2]

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I've discussed skydiving applications of this rule with DAN and since there is no research data on skydiving after diving they aren't willing to advise anything more aggressive. Personally I abuse the rule frequently but conservatively.

My concern is that perhaps we need to be more conservative then the recommendation.

And then there are the dive profiles- if you're sitting at 30ft for an hour, did you saturate the slow tissues that take the longest to clear, or take on virtually nothing given the max time for that depth?

Do you dive any differently - slower ascents, nitrox, long hangs at 30,20,15 - if you plan to fly soon after?

[Martini 0]

Consider this thread officially hijacked I guess. Although I might be more conservative with my dive profile if I plan to fly afterward (shorter/shallower dive) I'm more likely to vary my skydive activities based on the dives I've done. Also taken into consideration is the interval between end of dive and start of jumping. The whole thing is pretty subjective and makes me a guinea pig but I'm pretty considerate about it even though it's definitely pushing things. Maybe someday there will be a nice algorithm to account for all the variables but I wouldn't hold my breath. (pun intended) As for being more conservative than DAN's recommendation I think they did a pretty in-depth analysis recently to come up with the new figures. Naturally they don't guarantee not getting bent so being more conservative isn't a bad thing either. All I can tell you is that for my body what I'm doing hasn't caused any apparent effect. Naturally I don't do a couple of 150' deco dives and then run over to do some 13.5k wingsuit jumps either.

Sometimes you eat the bear..............

[FCipollo 1]

What's a "deco" dive and are you guys basically saying that I should wait at least 12 hours after taking a flight from NY to AZ before skydiving?

[billvon 2,989]

>What's a "deco" dive . . .

A SCUBA dive where a decompression stop is required. It can be planned or it can be due to a mistake (i.e. too much bottom time.)

>and are you guys basically saying that I should wait at least 12 hours
>after taking a flight from NY to AZ before skydiving?

No! If that was the case, you'd have to wait 12 hours after taking the ride to altitude before you could jump - the cabin altitude of a jump plane is a lot higher than the cabin altitude of a commercial airliner.

[twibbles 0]

The rule of thumb is that you shouldn't be flying after being diving. Jumping after flying is not an issue: poople do multiple jumps a day and that's not a problem, and every skydive starts with a flight up.
But if i'm wrong please feel free to correct me.

E

"In the beginning the Universe was created. This has made a lot of
people very angry and been widely regarded as a bad move."

[Martini 0]

Sorry we took the topic off course here Francesco.
As has been noted, flying in a commercial aircraft before or after skydiving is OK.
SCUBA diving after riding in an aircraft is OK.
Riding in an aircraft after SCUBA isn't recommended until after a 12-18 hour wait.

Sometimes you eat the bear..............

[kelpdiver 2]

Quote

What's a "deco" dive and are you guys basically saying that I should wait at least 12 hours after taking a flight from NY to AZ before skydiving?

To explain it in terms of physiology - your level of nitrogen in the blood is determined by the air pressure you're breathing in. If you go from a point of high pressure to low, some of that nitrogen diffuses out of your body tissues. If the change it too rapid, it forms bubbles that get trapped in the body and cause various effects.

The first level of understanding is that you can move to roughly half the pressure you were at before without great risk. So for most humans, a non issue. Sea level to 18k is about a halving of pressure. And you commonly breathe a higher percentage of O2 which speeds up the offgassing of nitrogen. So it's only on those jumps over 20k where you have to start thinking about it.

After flying in a passenger plane, you'll actually a tad bit safer to skydive in terms of nitrogen because your equilibrium is at 6-8000 ft. But once you land, you quickly return to the ground level equilibrium, so effectively it is like you never were on the flight. The one caveat here - flying tends to be dehydrating, esp if you drink alcohol or coke, and that does make you more sensitive to decompression illness.

Now to bring it back to why you read the warnings about scuba. At just 33ft under, you're breathing at twice the pressure of sea level. At 100ft, not a terribly deep dive, you're at 4 times. After a typical length dive, you surface with a considerable excess of nitrogen in your tissues and it takes upwards of a day to return to equilibrium. Not a problem if you stay at sea level, but if you go up to 10k in the time it takes an airplane to climb, you're dumping nitrogen much faster than your breathing system can handle. In reality, all scuba dives are 'decompression dives' in that your body is carrying excess nitrogen. The known models for handing it assume you stay at the pressure you surface at.

[AFFI 0]

Just make sure you have enough arm strength to flare because you arms might be worn out after flying so far (yuck yuck yuck)...

[FCipollo 1]

Hahah. Of course.