Am I just being paranoid?

[Jonathan]

Last weekend we got diverted to a different dive site because of the weather - this weekend we are planning to go to the same dive site for both days.

The problem - we have to travel (about 1.5 hours) back through some very hilly terrain and the instructor thinks we should be OK with the altitude - probably highest point being 600m - as we will take a long break after the last dive before heading off.

Coupled with this is the Japanese love for onsen (hot spring) after diving. I was always told by my instructors not to have a hot shower after diving (but never how long one must wait!). Our dive profiles will be 4 dives of about 30 - 40 minutes and a max depth of a about 35m with shallower second dives on both days.

I was not really concerned about the altitude too much but it all adds up, so am I just being paranoid?

Incidently - last week I only had a warm shower before the journey and not the hot soak. I probably should add I am not as skinny as the japanese I dive with!!

Cheers
Jonathan

 

[Dr Deco]

Dear Jonathan:

Regrettably, not everything that a diver can do has been tested. It is only when something specific arises in the interest of a government agency that funds might be expended for a study. Actual research by private groups is very limited.

The best case I can think of regarding temperature and diving concerns the problem with the explosion on the TWA plane that fell into Long Island Sound. During the recovery, more US Navy divers got DCS that would have been expected. A suspicion was that an environmental factor played a role, namely, warm water suits during the dive coupled with cold temperatures back on the dive barge.

A US Navy lab has been examining this question with animals (rats and pigs) as decompression subjects. They will try to combine various combinations (e.g., cold dive-warm depress; cold dive-cold depress, etc.) and note the outcomes. To my knowledge, the study is not yet complete.

Generally speaking, the condition of a cool diver on the bottom will result in a reduced gas uptake (unless the diver is cold and moving vigorously to keep himself/herself warm). The best topside condition is when the diver is warm on the boat and blood flow is very good. This promotes off gassing while on the surface.

I would not suspect that the condition described by you would be hazardous, although not all of the data is yet in.

Dr Deco

 

[Jonathan]

Doc, thanks for that - seems like I may have got things backwards, I must check out my books again..........


Jonathan

 

[Liquid]

You'r not just paranoid, there's something to it, aspecialy if you'r not as skinny as the others...

Hilly terrain after diving may pose a factor that increases DCS chances. I used to work at Eilat, the most southern point in israel. To get back to the north you need to travel through some mountains, up to about 800M, I belive. We recomended divers to have a small break before going north. Nothing to long, as they didnt go flying, and the drive untill you reach the mountains is about half an hour long, but still. We recommended a break for luanch before the drive, aspecialy for multi day multi dives profiles.

As for Hot-Springs after diving, it's another issue that increases threat for decompression. the ability of liquids to hold dissolved gasses is reduced when warmed. It's known that cold water hold more oxigen than warm water (which is the oposite of what happens with dissolved solid matters- you boil water to make coffe), so doing it right after a dive is also not recomended. Note that when I reffer to hot springs, I reffer to something way hotter than a normal warm shower. Being comfortably warm after a dive is good. Being over-heated, is not.

 

[blacknet]

Hello,

Liquid, please site your source for the info you handed out about driving to altitudes after diving.

Ed

 

[Liquid]

Blacknet-

As I said, it is a piece of advice we gave to divers where I worked. I can not reffer to any specific reliable source about it.

It is a problematic issue to begin with. DCS tends to acure hours, if not days after the dive (talking about the lighter version, I think it's type 1 but I may be confusing it). It is known that sometimes, several days after a diving vocation, people begin to develop simptoms of DCS, and are treated in HBO. We belive that hilly terrain right after a multi day-multi dive vocation can be a contributing factor to the issue. It is very hard to gather more detailed information about it, as DCS happens about once in 40000 dives, but logic says here that hilly terrain dosent differ very much from flying. of course the differentials are smaller, but here also we didn't recomend to wait 12 hours, only recomended to take a nice launch break before heading back north.

I can also tell you, about a friend of mine, an instructor that dives a lot, who had an incident of DCS though he was well within the no deco times. The DCS simptoms developed when he was in a vacation at the north, and on the way there he drove through the mountains. Does it prove anything?
No, of course not, but it could be a factor. There simply isn't enough information on the issue here to make a sollid statistic about it.

To sum it, what I intend to say, is that one should alwais be carefull. It isn't paranoya, as things do happen. Personaly, I wouldnt drive through mountains, after a dive, without a little break before it. Let's also remeber, that when diving at altitudes of 200 M and above, you must use a different table becouse the differential is enough to change the DCS chance of occurance.

 

[blacknet]

Hello,

So what you have stated is theory started by the local dive monkeys and not based on factual proof. Or did I miss something? The other thing is where did you get the info that DCS can take DAYS? Please quote those sources as well.

I also question your ratio of 1 to 40,000 as a) dives are conducted that can't possibly be listed and b) divers sometimes does nothing about the dci signs they develop and choose not to seek medical attention.

The info of waiting 12 hours before driving, please quote your sources for this as well.

Not trying to be harsh.

Ed

 

[Lost Yooper]

I think these type of questions are mostly dependant on how well you decompressed (ie. the deco procedures you used), and if you have any preconditions that would increase your chances of getting bent anyway.

Let me say it this way: if you did four dives to 130' in a single day and on each dive you shot to the surface at 60FPM+ and had a 1hr SI between each dive, then you might be taking your chances (you'd be taking your chances anyway). If you know how to deco out correctly (especially if you can use the right deco gasses), then all this stuff become mute, IMO.

I'd say, you're being paranoid.

Take it easy.

Mike

 

[Liquid]

So what you have stated is theory started by the local dive monkeys and not based on factual proof. Or did I miss something?

It's based on common sense.
Driving up a mountain isn't to different than going up with an air-plane.

The other thing is where did you get the info that DCS can take DAYS? Please quote those sources as well.

Oh my. Do some homework here yourself. Type one decompression (hope I'm not mistaking it with type 2, as I don't have the books in fromt of me) takes several hours to several days to develop simptoms. Not all cases are bad enough to couse problems right at the surface (actualy, most cases are not). I'm prety sure you can find some information about it in other threads in this folder, and in any site that deals with diving-medicine. You can also look for a thread posted by Khalid about a month ago, about an incident he had.

I also question your ratio of 1 to 40,000 as a) dives are conducted that can't possibly be listed and b) divers sometimes does nothing about the dci signs they develop and choose not to seek medical attention.

This was taken from the last issue of DAN europe magazine.

The info of waiting 12 hours before driving, please quote your sources for this as well.

12 hours before FLYING, not diving.
I said we recomended in cases of multi day-multi dive profiles, that people take a little launch break before they dirve to the mountains. Launch dosent take 12 hours!

 

[vicky]

Here you'll see at least a few DCS cases related to driving at high altitude after diving:

http://www.amtiusa.com/frst_ed/digpg13.htm

Personally, I used to drive quite frequently through the "high route" back from EIlat (up to 800meters). Once, after making four dives a day, the first one 42 meters, I felt realy bad on this road. I can't tell whether I was just very tired or it was something else. Since then I wait and take a good meal before driving home...good advice.