Do you/would you fly with an 19hr surface interval?

[GrumpyOldGuy]

^^ In an effort to be brief I glossed over the details on the computers and used the wrong word. Thanks for the clarification! I was trying to point out if you are diving at 55', the computer works on that depth, does not round up to 60 like you would on the tables. So often computer controlled dives exceeds the time/depth of table controlled dive. We tend to think that's OK, but when someone ask about getting even close to the no-fly time of 18 hours they get worried and feel the need to pad the time even if there are no other risk factors.

Padding the time is not bad, its even is good idea of you are overly tired, dehydrated, etc.... You just need to look at the overall state of your physical health at the time.

BTW: Depth averaging is sometimes used when planning dives to tables, I don't think its a great practice and outside the guide lines for rec divers, but if you search you will find plenty of discussion on it.

 

[Rhone Man]

That is quite a good way to paraphrase it:

It would probably not a problem, but if you don't know why it would probably not be a problem, then you probably don't have the skill set to assess those risks properly and would probably be better off playing by the official rulebook.

 

[Rickelpickel]

Call DAN, http://www.diversalertnetwork.org
Effective immediately, the phone number for the DAN 24-Hour Diving Emergency Hotline has changed. The new number is (919) 684-9111.
Once you give them your dive profile they can tell you how long to wait before flying.

 

[dallaskincaid]

My girlfriend is a physician and recently did training so she could prescribe hyperbaric treatment (as a diver, I've been extremely interested in this as well as you can imagine!). They went through the physiology of nitrogen loading and used dive tables for various scenarios. Her and other physicians at the training were confused as to why there was a 24 hour wait for recreational diving because your desaturation time is much much less than 24 hours. Now, granted, she won't let me bend the 24 hour rule "just in case." But she feels the 24 hour rule is EXTREMELY conservative.

 

[XS-NRG]

I would wait 24 hours for sure no matter what. My computer usually says 12-18hrs after my dives but I don't want to push it.

Now, I have only read half of the responses here so maybe I missed it but if the airline is competent and knows anything about diving and they find out you've been diving through casual conversation you could find yourself being refused on the plane. This happened to me 3 years ago. I was in Australia and dove the Whitsundays (discover dives as I was not certified yet) and had to take a take a flight a couple days later to head south and the cute flight attendant was asking me about my trip and what I got up to and once I told her I just finished diving she got extremely serious with me and demanded to know how long it had been since I last dove. I told her a couple days and then she relaxed and the flirting continued but I then asked her what she would have said or done if I had dove that day or within 24 hours and she told me she wouldn't let me on the plane if that were the case.

I'm not sure if this was airline policy or if she was a diver or just really well educated but the bottom line is that you aren't the only one affected if you get bent in a plane after diving. They have limited resources in the air and you can really screw things up for a lot of other people too and not just yourself. Don't be too flamboyant with your actions just because you are barely getting in under the wire. There are other people to consider as well.

 

[diverrex]

I would wait 24 hours for sure no matter what. My computer usually says 12-18hrs after my dives but I don't want to push it.

Now, I have only read half of the responses here so maybe I missed it but if the airline is competent and knows anything about diving and they find out you've been diving through casual conversation you could find yourself being refused on the plane. This happened to me 3 years ago. I was in Australia and dove the Whitsundays (discover dives as I was not certified yet) and had to take a take a flight a couple days later to head south and the cute flight attendant was asking me about my trip and what I got up to and once I told her I just finished diving she got extremely serious with me and demanded to know how long it had been since I last dove. I told her a couple days and then she relaxed and the flirting continued but I then asked her what she would have said or done if I had dove that day or within 24 hours and she told me she wouldn't let me on the plane if that were the case.

I'm not sure if this was airline policy or if she was a diver or just really well educated but the bottom line is that you aren't the only one affected if you get bent in a plane after diving. They have limited resources in the air and you can really screw things up for a lot of other people too and not just yourself. Don't be too flamboyant with your actions just because you are barely getting in under the wire. There are other people to consider as well.

On what basis do you decide to wait 24 hours? Why not make it 36 or 48 and be extra extra safe? I'll fly 18 hours after diving and I won't mention it to the airline. You can go somewhere like Bonaire where the weekly Saturday flight out leaves between 7:00 - 8:00 AM and I suspect 25% or more the plane has dived within the last 24 hours.

 

[supergaijin]

While extended safety stops may reduce the risk of DCS in most situations, the body will off-gas more efficiently on the surface than at a rest stop. So, extending the rest stop for the last dive may result in shortening the time to fly interval and carrying more gas onto the plane.

I was under the impression that the body is off-gassing more efficiently at safety stops than at the surface.

I remember a chart....somewhere.... somehow... that scientists were using to track micro-bubbles. A bunch of different profiles were used including direct ascents. The '10m/min ascent with safety stop' profile showed less micro-bubbling than a 10m/min ascent direct to the surface.

This would tell me that 5mins at a safety stop would be 'worth' more than 5 mins at the surface.

Saying that- with the described profiles of the OP, safety stops would do little effect as the long compartments are controlling the dive for which incredibly long safety stops are needed to do anything significant.

 

[Thalassamania]

Long repetitive dives, even shallow ones are the type of dive (as opposed to shorter deeper dives) that are most likely to get you into trouble with flying afterwards.

 

[Doc Harry]

I lost a $50 bet on DecoStop with a guy who wanted to fly 12 to 15 hours after technical deco dives. He flew, didn't get bent, and I lost $50.

 

[redacted]

I was under the impression that the body is off-gassing more efficiently at safety stops than at the surface.

I remember a chart....somewhere.... somehow... that scientists were using to track micro-bubbles. A bunch of different profiles were used including direct ascents. The '10m/min ascent with safety stop' profile showed less micro-bubbling than a 10m/min ascent direct to the surface.

This would tell me that 5mins at a safety stop would be 'worth' more than 5 mins at the surface.

Saying that- with the described profiles of the OP, safety stops would do little effect as the long compartments are controlling the dive for which incredibly long safety stops are needed to do anything significant.

May be a difference in the concept of efficiency. I think of it as maximum gas expulsion over time without violating NDLs. So, the body will give off more excess N2 (and other gasses) when held at 1.0 ATM than when held at 1.3. Micro bubbles, I expect, would be another story and micro bubbles, if present, should increase under lower ambient pressures. I agree that normally longer rest stops are harmless if not beneficial. But, when time spent at a rest stop must be deducted from the surface interval, there can be a down side to extended rest stops. Of course, this is assuming the risks of DCS are being managed first.