Can I calculate the time before flight by myself?

[GrumpyOldGuy]

Taking a full day off before flying after a week of diving is a great idea for lots of reasons. No argument from me there.

Doing the same after a single day of dives that you can plan via the NOAA tables is a different case. To say its just theory and don't push the limits for flying, while adhering to tables and pushing close to NDL on your dives is not consistent.

 

[diveprof]

This discussion does raise an interesting question - If a diver were to knowingly violate the recommended surface interval before flying and suffered DCS which resulted in an inflight medical emergency, and if the airline became privy to this information might they (or passengers) sue the diver for expenses incurred in a in-flight diversion due to the medical emergency?
I've not heard of a case where this has occurred -perhaps due to the confidentiality of medical information. Personally, I would not want to create such an inconveniece for those on the plane or a medical emergency for me by taking unnecessary risks. I prefer to be conservative and allow adequate time before flight. I bring this up because of a recent experience returning from Cozumel. While waiting in the airport at the gate for our return flight to the US, an elderly passenger sitting near me began experiencing chest pain and shortness of breath. A physician/diver on our flight spoke with the gentleman. The gentleman, who was overweight and did not appear to be in the best of health, admitted to the physician that he had been consuming much alcohol on vacation and had a pre-exisiting cardiac condition. The physician did a brief exam and listened with his stethoscope. He advise the individual to go to the local medical facility for evaluation. The gentleman refused as he wanted to go home. He later went into respiratory distress and was placed on O2. Airport personnel were on hand and provided the O2. The physician again advised him to accept medical care. He improved somewhat on the O2 and was able to board the plane without O2. The airline and the local EMS were aware of the situation and allowed him to board the plane. While I understand his desire to get home, I had very real concerns that we would be diverted on the way back if he went into distress again or worse that he would have a cardiac event and die.

 

[RonFrank]

Taking a full day off before flying after a week of diving is a great idea for lots of reasons. No argument from me there.

Doing the same after a single day of dives that you can plan via the NOAA tables is a different case. To say its just theory and don't push the limits for flying, while adhering to tables and pushing close to NDL on your dives is not consistent.

I dive alot and push NDL's often. I fly twice a year and rarely fly within 36 hours of diving. So I am comfortable pushing NDL's. I am not comfortable pushing no fly times. Do what you feel is safe. Personally I can take a day off after diving 7 days strait (for example) to give my body a break from constantly off gassing before a flight.

 

[farsidefan1]

I agree with those saying do what you are comfortable with. You have some good advice here. One thing I would add is the variability of your own body. I went on several trips diving 4 or 5 dives a day for 6 days then taking 24 hrs break and fly home with no problems. Then a trip to Coz, within 6 months of one of my extreme dive vacations I took a leisurely, for me at least, 2 dives for 2 days and 4 dives the third day. I spent the night in a decompression chamber, the day in the hospital and the next evening back in the chamber. Undoubtably my least dive intensive trip yet.... Just sayin, ..it happens and my computer never felt violated for a moment. Plan your dive, dive your plan but know you still might get screwed up.

 

[diverrex]

After researching the no fly issue I have come to the conclusion that I feel comfortable flying out as long as I have 18 hours since my last dive. We usually only do 2, maybe 3 dives a day, always only 2 on the last day, don't push NDL, stay more shallow on the last day and use nitrox when possible. I find it interesting that some are willing to push NDL all week long then go conservative about the no fly time. I'd rather be conservative all week then fly after only 18 hours. Whatever works for people I guess.

 

[GrumpyOldGuy]

I dive alot and push NDL's often. I fly twice a year and rarely fly within 36 hours of diving. So I am comfortable pushing NDL's. I am not comfortable pushing no fly times. Do what you feel is safe. Personally I can take a day off after diving 7 days strait (for example) to give my body a break from constantly off gassing before a flight.

We have a very different view point, I typically fly every other week for business and sneak in a dive day once a month with a flight typically 16-20 hours post dive. I wish I had a 7 day dive vacation, then 7th non dive day would not be an issue for me either.

I am not working on "what I feel is safe", I am working on tables published the the NOAA which carry the weight of significant scientific backing from people a lot smarter and more knowledgeable than I. In the absence of mitigating circumstances, I follow the data and dive with the parameters. If I track my dives with NOAA tables, then I can use their data. If I am lazy and rely on my computer, then I use the 12/18/24 hour rules.

 

[Adobo]

We have a very different view point, I typically fly every other week for business and sneak in a dive day once a month with a flight typically 16-20 hours post dive. I wish I had a 7 day dive vacation, then 7th non dive day would not be an issue for me either.

I am not working on "what I feel is safe", I am working on tables published the the NOAA which carry the weight of significant scientific backing from people a lot smarter and more knowledgeable than I. In the absence of mitigating circumstances, I follow the data and dive with the parameters. If I track my dives with NOAA tables, then I can use their data. If I am lazy and rely on my computer, then I use the 12/18/24 hour rules.

Amen.

I can't imagine how anyone could feel comfortable of feel safe with any practice absent any data. And just because the guy at the dive shop says "24hrs" doesn't mean there is any data or science to back that up.

 

[boulderjohn]

It is my understanding that DAN's initial 24 hour rule was a seat-of-the-pants guess with nothing to back it up. They then did the extensive studies that led to the 18 hour rule that, as Don said, has been in effect for a decade. If you read the details of the study, you will probably get the sense (as I did) that even the 18 hour rule is pretty conservative.

If I do a week of diving, I usually end up with a two tank dive the morning before I fly out. Even with a morning flight, that usually gives me at least 20 hours before I fly.

 

[Adobo]

It is my understanding that DAN's initial 24 hour rule was a seat-of-the-pants guess with nothing to back it up. They then did the extensive studies that led to the 18 hour rule that, as Don said, has been in effect for a decade. If you read the details of the study, you will probably get the sense (as I did) that even the 18 hour rule is pretty conservative.

If I do a week of diving, I usually end up with a two tank dive the morning before I fly out. Even with a morning flight, that usually gives me at least 20 hours before I fly.

There are divers doing tech dives in Lake Tahoe (altitude at lake surface = 6200ft.). Clearly, there is a way to consistently execute dives where you even exceed NDL and still not get bent even if you go directly to 6200ft elevation after completing the required safety/deco stop.

 

[boulderjohn]

There are divers doing tech dives in Lake Tahoe (altitude at lake surface = 6200ft.). Clearly, there is a way to consistently execute dives where you even exceed NDL and still not get bent even if you go directly to 6200ft elevation after completing the required safety/deco stop.

I am not really clear on your point here.

The flying after diving rule is based on the effects of a rapid ascent with at least a 2,000 foot elevation gain from your present altitude. If you are flying in a pressurized plane after leaving Lake Tahoe, then you are within the 2,000 feet of that altitude and should not have to wait at all.

Ascending from depth to the surface at altitude (or at sea level) is a totally different situation altogether. There you are making calculated stops along the way. How altitude affects those stops is a matter of great debate. UTD says it has so little effect it does not have to be considered in decompression planning. Most decompression algorithms, however, do think it makes a difference and plan accordingly.

You have a similar problem driving to altitude after a dive. The NOAA tables are helpful with that, because they have more increments.