PADI Scuba Diver v. Open Water Diver

[fisherdvm]

In support of Scubapatton, here is how DAN dealt with the subject:

Diving Medicine FAQs
Diving After Flying


Q: It takes most tourists 24 hours to get to our resorts here in Thailand. I notice that many tourists begin diving immediately when they arrive and often start drinking quite a bit of alcohol. Aren't they at greater risk for decompression sickness after their long flight if they begin diving right after they arrive? Shouldn't they wait one day before they begin diving?

A: Mild dehydration can occur on long flights, especially when travelers cross several time zones; alcohol consumption can also contribute to dehydration. Generally speaking, dehydration is thought to predispose a diver to decompression illness because the washout of inert gas (nitrogen, in diving) is less effective in a dehydrated individual.
If there were a relationship between diving after flying and DCI, we would expect to see a great deal of decompression illness on the very first day of diving -- indeed, some data suggests that there are more accidents on the first day of a planned multiday dive trip. Of the 88 cases reviewed from the Caribbean for 1994, 33 -- or 37.5 percent -- occurred on the first day. The remainder occurred on days two through seven. Given that there are thousands of tourist divers who fly to Caribbean and Pacific dive sites, these numbers are far too small to establish a cause and effect.

Although no one can insist upon a 24-hour waiting period after flying, such a conservative approach to diving after flying is a reasonable idea -- it gives divers an opportunity to rehydrate, adjust to a new climate and time zone, and rest up after a long flight.

 

[rawls]

In support of Scubapatton, here is how DAN dealt with the subject:

Diving Medicine FAQs
Diving After Flying


Q: It takes most tourists 24 hours to get to our resorts here in Thailand. I notice that many tourists begin diving immediately when they arrive and often start drinking quite a bit of alcohol. Aren't they at greater risk for decompression sickness after their long flight if they begin diving right after they arrive? Shouldn't they wait one day before they begin diving?

A: Mild dehydration can occur on long flights, especially when travelers cross several time zones; alcohol consumption can also contribute to dehydration. Generally speaking, dehydration is thought to predispose a diver to decompression illness because the washout of inert gas (nitrogen, in diving) is less effective in a dehydrated individual.
If there were a relationship between diving after flying and DCI, we would expect to see a great deal of decompression illness on the very first day of diving -- indeed, some data suggests that there are more accidents on the first day of a planned multiday dive trip. Of the 88 cases reviewed from the Caribbean for 1994, 33 -- or 37.5 percent -- occurred on the first day. The remainder occurred on days two through seven. Given that there are thousands of tourist divers who fly to Caribbean and Pacific dive sites, these numbers are far too small to establish a cause and effect.

Although no one can insist upon a 24-hour waiting period after flying, such a conservative approach to diving after flying is a reasonable idea -- it gives divers an opportunity to rehydrate, adjust to a new climate and time zone, and rest up after a long flight.

This is an excellent point that I hadn't even thought about while reading this thread. Although there is no stipulation that suggests not diving after flying, there are factors that predispose a diver to having greater risks of getting bent...as well as narced, all of which fisherdvm mentioned and including a big factor after a flight...fatigue. If you are tired you would also open yourself up to making mistakes.

 

[boulderjohn]

Boy, I don't see how.

First day: Let's say you do all your knowledge reviews before showing up. They still have to go over them with you, which takes some time. If you have great water skills already and are the only one in the class, it is indeed possible to do all the CW skills in a few hours. To get a normal sized class through all the confined water skills, though, takes a lot longer than that. Then you would have to get in at least one OW training dive that day. It would not be a day I would want to experience.

Second day: Three training dives. That is doable.

Of course, one way to do it is the way I was insrtucted when I took my OW class in Mexico: do all the CW work in an hour or two in a pool no deeper than 5 feet. Of course, you have to skip 75% of the actual instruction, but if your goal is to get it done rather than actually instruct, well....

I forgot to mention this:

Because they cut corners and skipped standards, and because I studied the book thoroughly before getting there, they were able to get it down to three days, not two.

 

[boulderjohn]

I flew to Thailand from the U.S., and I was certainly not wanting to dive that first day. Sleep was my prime concern.

 

[ekewaka]

I hate to get us back on topic of the post, unless others want to bash a diver's belief that actually erring on the side of caution and waiting ~24 hours may actually do more harm than good. Again, my basis for the comment was initial training from 11 years ago. Current research may have changed, but I will maintain caution and still get my dives in. You go get the 2-3 dives in while I wait topside by the pool soaking in the sun....

My comments were not intended as a personal attack. I just think the rule is ridiculous, and I would like to know where it came from. You certainly have every right to wait to a day before diving if you want. It won't do any harm other than missing a day of diving. As for myself, I will not blindly follow any rule from PADI, or NAUI, or anyone else unless I understand the theory behind it. It is possible that your instructor said that because he did not understand it himself. Maybe he was dyslexic and misread the rule. There are a lot of agencies and instructors saying things that have no basic in actual research.The rule of not diving after diving is not consistent with my understanding of decompression theory, and I doubt that there has ever been any research that supports it.

 

[ekewaka]

In support of Scubapatton, here is how DAN dealt with the subject:

Diving Medicine FAQs
Diving After Flying


Q: It takes most tourists 24 hours to get to our resorts here in Thailand. I notice that many tourists begin diving immediately when they arrive and often start drinking quite a bit of alcohol. Aren't they at greater risk for decompression sickness after their long flight if they begin diving right after they arrive? Shouldn't they wait one day before they begin diving?

A: Mild dehydration can occur on long flights, especially when travelers cross several time zones; alcohol consumption can also contribute to dehydration. Generally speaking, dehydration is thought to predispose a diver to decompression illness because the washout of inert gas (nitrogen, in diving) is less effective in a dehydrated individual.
If there were a relationship between diving after flying and DCI, we would expect to see a great deal of decompression illness on the very first day of diving -- indeed, some data suggests that there are more accidents on the first day of a planned multiday dive trip. Of the 88 cases reviewed from the Caribbean for 1994, 33 -- or 37.5 percent -- occurred on the first day. The remainder occurred on days two through seven. Given that there are thousands of tourist divers who fly to Caribbean and Pacific dive sites, these numbers are far too small to establish a cause and effect.

Although no one can insist upon a 24-hour waiting period after flying, such a conservative approach to diving after flying is a reasonable idea -- it gives divers an opportunity to rehydrate, adjust to a new climate and time zone, and rest up after a long flight.

If you read this post carefully, you will see that nowhere does DAN suggest that diving after flying increases your risk of DCS. They are simply saying that there is a correlation between diving after flying and increased occurrences of DCS because divers are drunk and dehydrated. You must remember that correlation does not equal causation. I am not suggesting that anyone should dive while dehydrated, or after drinking alcohol. That will significantly increase your chances of getting bent. It was the alcohol and dehydration that caused them to get DCS, not the flying.

 

[Bubble Junky]

In a few days I'm leaving for an 8 day quickie trip to Thailand.

Where abouts in Thailand you headed ?

It was the alcohol and dehydration that caused them to get DCS, not the flying.

Yeah, but it's hard to stay properly hydrated on a long haul flight - being on a flight for a long period is dehydrating. You could say that flying after diving doesn't cause DCS, it's the reduced pressure, not the actual flying that does this, but that'd be a crap argument.

 

[fisherdvm]

If you read this post carefully, you will see that nowhere does DAN suggest that diving after flying increases your risk of DCS. They are simply saying that there is a correlation between diving after flying and increased occurrences of DCS because divers are drunk and dehydrated.

I've read the post carefully, and DAN certainly suggests that diving immediatly after long flight increases your risk of DCS. The front loading of 1/3 of the cases on the first day certainly SUGGESTS increased risk of DCS.

Correlation was not made to drunk divers or dehydration - these are just simply guesses by the author.

Correlation was made between the first day of diving after flying and increased incidence of DCS.

Causal relationship was not made, simply due to the low number of cases (88)....

But certainly, a larger scale study done overtime might lead to a causal relationship.

Divers beware, I think, this is what they are trying to say.

 

[Hinalo]

I appreciate the DAN article post and it sounds plausible that fatigue and dehydration associated with long-haul flights could be potential risk factors. It's something to think about.

 

[tracydr]

That's no fly after diving, not before.