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Discussion Starter · #1 ·
Hi all,
This isn't specifically a Vision question but I'm hoping some clever world traveller will be able to help....

I'm up in Scapa having a great time diving my Inspo, 7.5 hours so far, probably 3 more tomorrow. I'm flying home from Inverness on Saturday at 11.30 AM. Is there any way I can sensibly calculate or show my nitrogen loading on the the Vision or Log viewer? I can't see anything remotely like the 'No Fly' time on OC dive computers. I'm currently planning to stay out of the water for 24 hours prior to flying home so I should miss the last dive (although that would still put me on the Markgraf for 90 minutes in the morning).

Any advice/comments gratefully received !
 

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Hi all,
This isn't specifically a Vision question but I'm hoping some clever world traveller will be able to help....

I'm up in Scapa having a great time diving my Inspo, 7.5 hours so far, probably 3 more tomorrow. I'm flying home from Inverness on Saturday at 11.30 AM. Is there any way I can sensibly calculate or show my nitrogen loading on the the Vision or Log viewer? I can't see anything remotely like the 'No Fly' time on OC dive computers. I'm currently planning to stay out of the water for 24 hours prior to flying home so I should miss the last dive (although that would still put me on the Markgraf for 90 minutes in the morning).

Any advice/comments gratefully received !
No idea, but I would take the Friday off if it were me.

Matt.
 

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Huntin' wabbits....
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How can a computer accurately show your 'nitrogen loading?' Surely to do this you would have to impale yourself with a hyperdermic needle and analyze the contents?
Surely the best option is to follow the widely accepted durations post dive before jumping on a plane? Or sit in your hotel chugging O2 before your flight in the hope that it might help?
 

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Discussion Starter · #6 ·
How can a computer accurately show your 'nitrogen loading?' Surely to do this you would have to impale yourself with a hyperdermic needle and analyze the contents?
Surely the best option is to follow the widely accepted durations post dive before jumping on a plane? Or sit in your hotel chugging O2 before your flight in the hope that it might help?
With respect Jon you really need to look at how a dive computer works - by modelling the nitrogen loading in the tissue compartments of your body. Admitted it is a model and compartments don't really exist but if you dive with a computer and trust it to calculate your no-stop time or decompression stops you clearly accept that the model works.

There are no firm rules for no-fly times, DAN suggest 12 hours minimum for non-deco dives but basically they propose doing a risk analysis based on the risk you you are willing to accept of getting bent. Red Sea Shadow's link above has an interesting article with a quote from NASA stating that they do no allow astronaults to fly within 10 hours of underwater EVA training and that's after an hour on O2 at 1 bar. Sounds good to me.
 

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Huntin' wabbits....
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Major - I am well aware of how computers work, but thanks for the quick lesson.
My point is - everybody's metabolism is different. Why bother pushing the limits of what may or may not result in a bend?
There are widely published and accepted 'norms' for adequate time before flying. If i was on a aeroplane that got diverted because someone thought they could push the boundaries and got themselves bent i would be slightly pissed - wouldn't you?
 

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Duvet Diver
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I've dived the Friday in Scapa and caught the 15:30 flight on the Saturday. I'd just been out the water 24 Hrs.
It's a personal decision you have to make after considering your profiles and your attitude to risk.
Simon A
 

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Major - I am well aware of how computers work, but thanks for the quick lesson.
My point is - everybody's metabolism is different. Why bother pushing the limits of what may or may not result in a bend?
There are widely published and accepted 'norms' for adequate time before flying. If i was on a aeroplane that got diverted because someone thought they could push the boundaries and got themselves bent i would be slightly pissed - wouldn't you?
Interesting.

Whether you dive tables or a computer, you are trusting a mathematical formula that assumes all divers are the same. As most divers that follow their tables or computers don't get bent I can't see any issue allowing the same tables (the BSAC 88's allow you to calculate when you can fly after diving) or a computer let you know when you have no supersaturation and are good to get on the plane.

Waiting a day or two just to be on the safe side might be widespread practice, but would be overkill for a single short shallow dip IMHO.

Speaking practically, I am not sure the Vision controller does give a no fly time, but I shall be double checking when I get home as I am off to Egypt with my YBOD Sunday... As we have a full day off at the end of the trip I should be fine in any case.

Talking of overkill, when I go to Jamaica with Virgin they use DAN's recommendation for multi day deco diving and have a 48h no fly rule. Even worse, the dive shop check your ticket and ban Virgin divers from booking dives during this time, so anyone doing the same trip with another airline gets another day diving.
 

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Discussion Starter · #10 ·
Interesting.

Talking of overkill, when I go to Jamaica with Virgin they use DAN's recommendation for multi day deco diving and have a 48h no fly rule. Even worse, the dive shop check your ticket and ban Virgin divers from booking dives during this time, so anyone doing the same trip with another airline gets another day diving.
That's pretty awful - simple solution though is to not fly Virgin!

24 hours would seem to be more than enough desat time even after a weeks deco diving. I did end up taking friday off for some (very pleasurable) sight seeing and flew home today but I'm pretty sure I could have dived on Friday had I wished and had an 18 hour break. It's a shame the Vision doesn't have a desat time on it and I'll be picking up a VR3 or similar as a backup for future diving which will have.
 

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Discussion Starter · #11 ·
Major - I am well aware of how computers work, but thanks for the quick lesson.
My point is - everybody's metabolism is different. Why bother pushing the limits of what may or may not result in a bend?
There are widely published and accepted 'norms' for adequate time before flying. If i was on a aeroplane that got diverted because someone thought they could push the boundaries and got themselves bent i would be slightly pissed - wouldn't you?
Jon - I appreciate everyone is different but tables/computers are designed to conservatively cover the 'average' diver, they aren't individually fine tuned but I accept your point about about not pushing and getting bent, and yes, if some idiot of a diver got bent on a plane and made me late home I would be pissed!
 

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Ultimate Planner
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No clue how to show your nitrogen loading on your CCR, but there's an article about accelerating no-fly time in the first issue of Tech Diving Mag. Thought you might be interested.
Now there's another approach to calculate the no-fly time acceleration. it's described in the fourth edition of Tech Diving Mag. Also there's a deco planning software that calculates the no-fly gain called Ultimate Planner (not free, though).
 
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