Scuba Divers question.....

Cruzinchris

Cruzinchris

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Cruzinchris
I am thinking about flying from where I live in Santa Cruz, CA to Santa Barbara for 3 days of Scuba diving.

We have all heard during our dive training to avoid flying after diving. Would there be a danger if one was to fly at no higher than 1000’ MSL for a couple hours to get home?
 
Considering that commercial flights are usually pressurized to 8000 MSL, it would seem the altitude need not be that high to be dangerous. That said, I wouldn't think 1000 MSL would be dangerous as it is easy and routine to drive to that altitude just going inland a bit - but that's assuming you could be 100% certain to stay that low. I would also be a little concerned about the speed of ascent.

I would put this question to a physician experienced in dive-related medicine.
 
I'm also a diver - it's really not worth the risk and easy to avoid. Assuming your dive is <60', then I suggest you wait 8 hours after diving before flying.
 
rk911 said:
i've always understood that no-fly-after-dive referred to commercial flights at high altitude. check https://www.leisurepro.com/blog/scuba-guides/flying-after-diving-how-long-should-you-wait/
Click to expand...


Commercial airliners are pressurized to ~7000', so I believe that's what the guidelines address.

I wouldn't be too worried about a flight to 1000' unless that was a typo and he meant 10,000'. That assumes none of the dives required staged decompression. Personally, if I were doing this, I'd only do one dive on the last day and keep the dive less than 30' and less than an hour, and I'd probably still wait at least 6 hours before flying to 1000'. That's just personal opinion, with no deco modeling to back it up. I don't have any models installed on this computer, unfortunately, but it's known that slower tissue groups take several days to completely outgas, so multiple days of diving can stack up a decompression debt on you.

The problem isn't entirely altitude; rate of ascent also matters. Just like when you're ascending from a dive. Most deco computers try to hold your ascent rate to <30' per minute at the shallower depths. Of course that number applies underwater, not in the air, but the principle is the same. Riding a rocket to 1000' in 5 seconds is more likely to bring on a bends hit than ascending 1000' in 3 minutes.
 
Cruzinchris said:
I am thinking about flying from where I live in Santa Cruz, CA to Santa Barbara for 3 days of Scuba diving.

We have all heard during our dive training to avoid flying after diving. Would there be a danger if one was to fly at no higher than 1000’ MSL for a couple hours to get home?
Click to expand...
Strangely worded question, normally divers are precise when they specify wait time between diving and flying. Second I would never consider flying at 1000’ between Santa Barbara and Santa Cruz, even if you plan on following coastline, I wouldn’t even like to fly at 3000’, not enough altitude to react when something goes wrong.




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Thanks everyone for the input on this. I think I will take the day off before flying.
 
Speed of ascent is a concern - think of a coke bottle. If you open it slowly you get a few bubbles fizzing up. If you open it quickly, a lot of bubbles fizz up. It is exactly the same principle. Don’t be the coke bottle opened quickly.

That said, 1000’ is not much different than sea level. Remember that air and water pressure exist because of the weight of all the air and water above them. 1000’ is practically nothing as a percentage of the height of all the air above you.
 
DesertNomad said:
How would you dive in Lake Tahoe which is at 6200'? I grew up there and people dive in the lake all the time.
Click to expand...

They use dive data /computers specific to high altitude diving that is far more conservative than what folks diving at SL use.
 
I was part of (the same way a lab rat is 'part of') a study at Duke by DAN, and I think USN, doing chamber dives and then flights with shortened intervals. I've since forgotten the exact profile of dives and flights I did, but it was pretty short relative to the recommendations, and we only had one guy in our group get pulled for having bubbles on the wrong side of his heart on Doppler.

That said, why not wait? We had the benefit of already being in Duke's hyper/hypo chambers if things went sideways.

Fun fact... My ink pen i brought in for crosswords didn't make it either.
 
Let's do some math.

At a depth of 33 feet you're at 29.4 psi, but heck, let's use inches of mercury instead (for obvious reasons), so 59.85 inHg.
At the surface you're at 29.92.
Code: 
height  inHg   diff from MSL   equivalent water depth
1000    28.86     1.06                     1 ft
2500    27.32     2.6                      3 ft
5000    24.90     5.02                     6 ft
7000    23.10     6.82                     8 ft

The moral of this story...... the math is a bad indicator of the danger. There have been a multitude of documented cases of the bends from flying even short flights at modest altitudes. Set your dive computer to high altitude mode and see how much difference you get in bottom time. It's significant.

Wait the day. Don't take the chance. You may have dived 50 times and were just on the border of a problem, and this 1000 feet will be the difference. Imagine getting the bends while PIC.

If you really want to dive 8 hours from flying, I'd put my dive computer on high altitude setting and make short dives to low depths.
 
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