Driving Over a Mountain After Diving

[AndrewA]

I agree with previous posters that a surface interval of 3 hours is more than adequate before making the ascent. However I would like to bring up another point. In this and also a recent thread in the incidents section the issue of driving over mountains after a dive has been discussed but nobody mentioned the point that in order to get to the dive site the same ascent and decent had to be made before the dive. This may have implications for dive planning as well.

 

[vladimir]

.....

 

[pjones]

In order to get to the dive site the same ascent and decent had to be made before the dive. This may have implications for dive planning as well.

As you drive up the mountain you would off gas slightly possibly reducing your nitrogen levels enough to give you a few extra minutes under water. Are you suggesting we extrapolate from the table and add some bottom time? Are you inquiring weather or not the drive in will cancel the drive out for the same reason as mentioned above?

If the latter of the two than I would be worried that my prep time before the dive would bring my nitrogen percentage back to normal levels before I hit the water. Although I am still pretty slow to get ready...

I'm just not too sure how you were planing on incorporating this into the dive plan.

 

[nielsent]

I believe that the problem is the possibility of reaching supersaturation and possibly the bends by decreasing overall ambient pressure when increasing in altitude. However, it is not exactly to extreme heights. I did my deep diver course in one day at sea level, and then had to drive the next day to my home that requires a drive over a mountain pass that is 6000ft. As far as a recreational situation is concerned, an extreme scenario. I had around 8-10 hour surface interval from going to 130fsw to 6000 feet altitude and had no problems. I am not saying that this will be the same for everyone, but I am certain that based on the statistics and physics that it would be highly unlikely for something deadly to happen.

 

[Mr Carcharodon]

The drop in pressure from sea level to 2000 feet above sea level is .04 bar, or 2.3 feet of sea water. Common experence suggests that depth changes of a few feet are not significant from a decompression standpoint. Also you could get a similar pressure drop due to a low pressure front coming through. I am not aware of rain storms triggering DCS which you might expect if pressure changes of this level were significant. Also recall that this pressure change is less than 5% of the m value even for the most sensitive compartment, again suggesting a small effect.

 

[captndale]

As others have said in various ways, the profile you propose should pose no significant problems. In the future, however, if you are driving to altitude after a dive you might consider planning the dive as an altitude dive. You just use equivalent depths assuming you are diving at the greatest altitude to which you will be traveling. This results in a very conservative plan.

 

[Hatul]

As others have said in various ways, the profile you propose should pose no significant problems. In the future, however, if you are driving to altitude after a dive you might consider planning the dive as an altitude dive. You just use equivalent depths assuming you are diving at the greatest altitude you to which you will be traveling. This results in a very conservative plan.

Yes, that's my thinking as well. As you say it is a conservative method, but it's simple and logical.

Adam

 

[drbill]

We had a local instructor here on Catalina who was doing OW class dives with her students (thus shallow dives). Afterwards she drove back to her BF's home, reaching 1610' elevation along the route. She developed DCS symptoms, was treated hyperbarically and to the best of my knowledge has not dived since then.

Her dives were all shallow from what I remember with no surprises. However, she did do multiple dives that day rather than just one. You suggest you are doing just one.

I tend to be pretty cautious about elevation after diving (our terrain is hilly, but not mountainous), but my dives are often much deeper.