Flying on Monday morning after diving weekend?

[Lorenzoid]

I just talked to the diving school The outcome:

- I will do the deep dive on day 1, instead of day 2 in the morning
- The last dive on day 2 will be with Nitrox and very shallow
- The last dive will also be earlier than usual, so that I finish at about 1 PM and have 18 hours between my dive and my flight
- If, for one reason or another, the last dive on day cannot be done that early, it will be moved to another day after my business trip

Sounds reasonable, and glad you discussed it with them. The issue of flying-after-diving is something that meshes nicely with what is taught in an AOW course, and it only makes sense to bring it up for discussion.

As you likely saw above, 18 hours is in line with what DAN suggests is reasonable:

"For multiple dives per day or multiple days of diving, a minimum preflight surface interval of 18 hours is suggested."

 

[diver 85]

What are your 2 dives Sunday like???---keep em 'shallow' &.........IMO, you'll be fine-----if you don't bust da tables........

 

[pkpuffer]

Doesn't your dive computer tell u when it's ok to fly?

 

[Rhone Man]

There are a lot of opinions on the subject, and lot of pseudo-science (although very little hard data). My own approach tends towards the more pro-risk side for various reasons.

• When I was first certified, the standard PADI tables admonished you not to fly within 4 hours of diving - or 12 hours if you had been engaging in decompression diving. I think we all recognise that is too risky now, but just pointing it out.
• The reduction is partial pressure surrounding the body from flying is actually quite modest. No doubt it can accelerate off-gassing in a way which can be bad, the risks are most acute when you have high levels of nitrogen absorbtion. After 12 hours, the vast bulk of the gas is gone and your risk is commensurately lower.
• Be smart. Keep your last dive shallow, and make your deep dive short. And stay well hydrated.
• Ultimately it is your own decision on risk. But treat it like a decision and make an informed decision rather than "winging it". Consider the different risks of a short haul flight (where if something goes wrong, at least you are back down soon) and a long haul flight - there is a much greater limit to what I will do before getting on a 15 hour flight over the Pacific.

Last time I pushed the envelope on this was when I was diving in the Philippines. I did three dives on the Monday and then flew on the Tuesday. But (even though they were shallow dives) I did them on nitrox, and kept the last one above 30 feet. My dive computer cleared after 17 hours and, as it happened, about 30 minutes before boarding.

 

[rivers]

I flew about 14-15 hours after finishing a week of diving (15 hours or so in water, depths up to 40m, and deco). The day before flying, diving was 33m max depth, 15 minutes of deco. No issues. take that as you will.

 

[sphyrnidus]

It is amazing how little hard evidence there is on this important subject. Even Dan hasn't fully tackled the subject. Like it says on there site: research is on going.
Referring to what your PDC is imho quite useless, because the algorithm's in a pdc are for sure not up to par with current scientific data.

That said 18 hours looks to be the standard after multiple no-deco dives. 12 hours after a single dive and > 18 hours after a deco dive. Of course these are all empirical and scientist will tell you that "empirical" is not very hard evidence (that would be something like double blinded, placebo controlled studies and that hard to execute, if not impossible)

And as people tend to dehydrate while diving, in the tropics and while flying, which certainly is not helpful in preventing dcs: be sure to drink a lot, 2-3 l on the day before you fly. It's better to have to pee a lot while flying, better anyway than getting bubbles.

 

[Lorenzoid]

It is amazing how little hard evidence there is on this important subject. Even Dan hasn't fully tackled the subject. Like it says on there site: research is on going.
Referring to what your PDC is imho quite useless, because the algorithm's in a pdc are for sure not up to par with current scientific data.

Agreed. The no-fly time displayed on a PDC is probably the least reliable information the computer provides. It is simply reflecting the fact that there is little scientific data from which to base a reliable computation. What it displays is no better a guess than you could make yourself.

 

[Searcaigh]

That is one of the problems when looking at the clinical aspect of DCS, there are a lot of variable factors involved but you can do a lot to mitigate any possibility of a hit, one of which is to stay well hydrated as sphyrnidus mentioned above.

As tempting as it may be when socialising after dives, avoiding alcohol also helps.

Many years ago … in fact 16 years ago … I boarded the plane to Dubai from Maldives after 29 dives in 6 days all on air, and my computer cleared as I boarded.

Last dive was 1 Hr 11 mins on Vadoo house reef, max depth 10M and no fly time was 18 hrs and 3 mins …. log books do come in useful

---------- Post added September 5th, 2014 at 05:36 PM ----------

I flew about 14-15 hours after finishing a week of diving (15 hours or so in water, depths up to 40m, and deco). The day before flying, diving was 33m max depth, 15 minutes of deco. No issues. take that as you will.

Hi rivers were you using trimix?

 

[EFX]

Referring to what your PDC is imho quite useless, because the algorithm's in a pdc are for sure not up to par with current scientific data.

The no-fly time displayed on a PDC is probably the least reliable information the computer provides.

A more accurate indication of the tissue's N2 status is the desat (desaturation) time remaining on your DC. This is the amount of time remaining until the slowest tissue compartment will fully desaturate from depth (or if you prefer will saturate to surface pressure). On my DC it's displayed until it counts down to zero then it's not displayed. Since this calculation comes from a model (computer algorithm) it's not an empirical indication of what's actually happening in the body. There are four issues that determine your susceptability to getting DCS: the depth, amount of time at depth, gas mix, and perfusion. The first three are measurable and repeatable where empirical methods can keep you out of DCS. The fourth, perfusion or blood flow to the tissues, is not measurable at least to any practical degree for scuba divers. It is the blood that carries the N2 from the tissues to the lungs for offgassing. Until we can get sensors in the body to measure N2 flow out of the tissues or at least measure the N2, both dissolved and free in the blood, then DC's will always be a best guess solution.

 

[rongoodman]

I'm Nitrox-certified already, so I could potentially do my 2 dives on Sunday with Nitrox.

Why not just do them all on Nitrox? You'll end with with less N2 loading of the slower compartments, which would be the only ones possibly at issue before your flight.