Flying after diving

[Thalassamania]

PADI says 12 hours after one dive and 18 hours after multiple dives. But in the end you should follow your dive computers guidelines. If it says 24 hours then go with that. It's not worth a case of the bends for 2 dives.

PADI and your computer are more concerned with CYA than with your understanding the issues and making an intelligent and informed decision. Do your research and make up your own mind.

 

[Charlie99]

SugarInWater, as you can see opinions vary.

The crude rules of 12 hours or 18 hours or 24 hours are oversimplifications. They make as much sense as saying "Max dive depth is 70'. Max dive length should be 20 minutes, followed by 1 hour SI" That rule would keep you just barely inside NDL limits, but most people would find it ridiculously limiting.

If you have been pushing the NDL limits by "riding the NDL" on your computer as you ascend back up from multilevel dives, then 18 hours may not be enough. That way of diving leaves the slower compartments with very high loadings ..... higher then either short deep dives, or long shallow dives.

I have often faced the same decision. My normal response is to do the dives the morning before, even if my flight is 8AM or 9AM.

I would also be not quite as aggressive in my profiles on my last dive day, and might even use nitrox.

 

[TexasKaren68]

I'm just starting out diving and during class last weekend my instructor told us a story. He'd been diving for a few days and waited about 17 hours before flying home. Well, on that flight his fingers and forearms went completely numb. After he landed (fingers/arms felt better once he was on the ground) he called a doctor friend of his who said that yeah, he was bent. Now, my instructor waits about 30 hours before flying after doing multi-day dives, which means no dives at all the day before his flight home.

 

[theduckguru]

Here's my question...

I've got a 7:40am flight on a "puddle jumper". It's a 20 minute flight and I'm not sure about altitude but would expect it to be 3000 to 4000ft.

Later that day, at 1pm to be precise, I board "big boy airplane" to fly home.

Can I do two morning dives the day before this travel? Both dives would end before the 1pm, 24 hour cycle for the longer flight but obviously conflict with the first shorter flight.

Thanks in advance.

You can't assume a very low altitude based on a short flight time. If it's aturbin aircraft, you'll be flying a lot higher than 4000ft.

 

[fresh_fish]

Look on FlightAware - Flight Tracker / Flight Status / Flight Tracking and look up the flight number. You can see the other recent flights and what altitude they flew at. That's not to say at any time they could be told to go to a different altitude, but it gives you an idea of the typical for that flight.

 

[fjpatrum]

For what it's worth, the "puddle jumper" flights I've been on to the islands have generally been flying in the 6k-8500 ft altitude range, not the 3-4k.

Also, pilots don't get to choose their altitudes on approach to major airports. They are directed by ATC.

I'd say if it's a major concern for you, skip the second dive of the day and enjoy yourself snorkeling or sunning on the boat.

 

[SugarInWater]

Thanks for all the comments and suggestions. I'm diving with two of my kids, aged 18 and 15, we're all AOW.

I've always prided myself on the fact that we've had good training and I think we're all careful, conservative divers. When we're in the water, they are my dive buddies not my kid and we behave accordingly. My computer says 24 hours and my training says 24 hours. The very, very bad downside isn't worth an extra dive or two. I've never "pushed it" before why start now.

Thanks again for all the feedback.

Mike

 

[berk]

In addition to just raw time, make sure you're flights won't turn into an absolute disaster with rescheduling if the last dives don't go well, forcing you to stay to make sure you haven't been bent. I guess that would depend on how aggressive you are diving as well.

Make sure you feel well and nothing funny happened on the dives close to your flight. DCS can be and often is delayed. Jumping on the plane can be the catalyst to set it off or make it worse.

This fellow lays out this type of situation.

http://www.scubaboard.com/forums/as...t-delayed-dcs-symptoms-delayed-treatment.html

I have a very sensitive left shoulder and need to be cautious about my profiles. I was driving on I-476 back to Philly from the St. Lawrence and felt my ears popping. My shoulder did a little pop of a different kind right as I was thinking about pulling off for gas. Granted this was 6-7 hours after the dive. Elevation can't be much more than 2-3000', but had I stayed at the same elevation for another day I doubt anything would have happened.

I've been in your position and know it's such a temptation since you've spent the time and money to go somewhere really exciting for a dive vacation and want to get in as much as possible.

- matt

 

[bleeb]

In addition to just raw time, make sure you're flights won't turn into an absolute disaster with rescheduling if the last dives don't go well, forcing you to stay to make sure you haven't been bent. I guess that would depend on how aggressive you are diving as well.

Make sure you feel well and nothing funny happened on the dives close to your flight. DCS can be and often is delayed. Jumping on the plane can be the catalyst to set it off or make it worse.

That brings up a good point that's been identified in a few previous A&I threads as not always being well understood: AFAIK, the various versions of 12/18/24-hour recommendations all assume that you're free of DCS symptoms during that period.

Another sometimes missed assumption is that you haven't exceeded NDLs at any point in the preceding dive series (presumably especially the last recent dives).

 

[Thalassamania]

I'm just starting out diving and during class last weekend my instructor told us a story. He'd been diving for a few days and waited about 17 hours before flying home. Well, on that flight his fingers and forearms went completely numb. After he landed (fingers/arms felt better once he was on the ground) he called a doctor friend of his who said that yeah, he was bent. Now, my instructor waits about 30 hours before flying after doing multi-day dives, which means no dives at all the day before his flight home.

It sounds to me more like making macho out of a molehill. Unless he was diagnosed by relief of symptoms at depth, he was not properly diagnosed with DCS. No competent Hyperbaric Physician would diagnose DCS over the phone, if fact no competent physician of any specialty would do so ... they'd have insisted that he travel to the nearest chamber. BTW, with an untreated bends case in his jacket he should not be diving at all, ever again.