Before Flying

[TMHeimer]

Question for Instructors/DMs: I've never gone on a week long diving trip. I know you wait a minimum 12 hours before flying back. The place has shore diving. Is it safe enough to do a couple of shore dives to 30-40 feet the afternoon of the last day? Or is it best to do none at all? I figure the first few days will be all the deep boat dives. Maybe do the shallow shore dives 2 days before leaving and none the day before to be sure? Thanks.

 

[diver 85]

You answered your own question-------ie 12 hours before flying on NCD'ing....Let me tell you a story----I remember a trip we(family) made to Roatan in '94--Fantasy Island--before computers for us.....I made 4 dives daily(3 boat dives & the wreck~??40' deep?) for 6 days.....24 dives total that week. The last day a Saturday I made them, was out of the water by ~8PM that evening & flew the next morning, Sunday, back to N.O.......

EDIT: I was 43 Y.O. then....

 

[hudson]

It sounds like you are talking about diving the day BEFORE your flight?

There is a DAN study that suggest with a minimum of 17 hours before your flight after repeated dives you should be fine. (12 hours applies for a single dive)

If not, and you are suggesting diving the same day then read:
http://www.scubaboard.com/forums/as...0-shallow-dives-during-no-fly-desat-time.html

 

[k ellis]

The time frame on the no fly time has changed a couple of times one suggest 12 hours one is 18 and another is 24. Ive dove 14 hours before a flight and never had any problems but that was on my introductory to scuba dive. Id say its best to be safe rather than sorry and wait 24. Thats just me though because Scuba incidents can be fatal if not permanent if not taken seriously

 

[LeadTurn_SD]

Question for Instructors/DMs: I've never gone on a week long diving trip. I know you wait a minimum 12 hours before flying back. The place has shore diving. Is it safe enough to do a couple of shore dives to 30-40 feet the afternoon of the last day? Or is it best to do none at all? I figure the first few days will be all the deep boat dives. Maybe do the shallow shore dives 2 days before leaving and none the day before to be sure? Thanks.

I believe the current recommendation is as follows:

For a single no-decompression dive, wait at least 12 hours before flying.

For multiple dives per day or multiple days of diving, wait at least 18 hours before flying.

For dives requiring decompression stops, wait a lot longer than 18 hours (there is no "official" recommendation on number of hours after a deco dive that I'm aware of, other than wait >18 hours )

I believe many current recreational dive computers will list the "Time To Fly" countdown as 24 hours after surfacing from the last dive.

Be conservative.

I'd personally wait at least 24 hours before flying after doing multi-day diving, unless there was a very urgent reason to leave sooner (in which case I'd just skip the dive). If there was a reason to leave before 24 hours had passed, I'd use the USN "Required Surface Interval Before Ascent to Altitude After Diving Table, (you also need to use USN dive tables, not PADI RDP, to get the correct Group Designation).

However, when I look at what the USN Ascent to Altitude table allows for 8,000 feet (cabin pressure), it is actually pretty similar to DAN's recommendation. Take a "typical" AL80, single tank, within-NDL reef dive: Example, a single "square profile" 60 feet, 40 minute dive would call for a 12:05 surface interval before flying using the USN tables... so really the DAN recommendation of at least a 12 hour wait after a single dive is actually not all that conservative.... so unless you do a very shallow single dive, I'd think hard about jumping on an airliner the same day....

 

[Thalassamania]

Question for Instructors/DMs: I've never gone on a week long diving trip. I know you wait a minimum 12 hours before flying back. The place has shore diving. Is it safe enough to do a couple of shore dives to 30-40 feet the afternoon of the last day? Or is it best to do none at all? I figure the first few days will be all the deep boat dives. Maybe do the shallow shore dives 2 days before leaving and none the day before to be sure? Thanks.

There are lots of different recommendations for how long to wait before flying, ranging from 12 to 48 hours. In the old days the recommendation (and this is the one I've followed my entire life) is that you need to be in U.S. Navy Group-C before you fly.

In any case, your idea of diving shallow is a very bad one, shallow dives tend to be longer dives, and thus put nitrogen into slower tissues that you have to wait longer to clear before flying. While it may seem counter-intuitive, you are in far better shape to a make a short deep dive which will clear much faster.

If you have to fly soon after diving breathing pure oxygen on the suface (or, even better at 10 to 15 feet) can be a good idea. Two hours of pure oxygen at sea level will take you from Group-N to Group-A.

 

[LeadTurn_SD]

There are lots of different recommendations for how long to wait before flying, ranging from 12 to 48 hours. In the old days the recommendation (and this is the one I've followed my entire life) is that you need to be in U.S. Navy Group-C before you fly.

In any case, your idea of diving shallow is a very bad one, shallow dives tend to be longer dives, and thus put nitrogen into slower tissues that you have to wait longer to clear before flying. While it may seem counter-intuitive, you are in far better shape to a make a short deep dive which will clear much faster.

If you have to fly soon after diving breathing pure oxygen on the suface (or, even better at 10 to 15 feet) can be a good idea. Two hours of pure oxygen at sea level will take you from Group-N to Group-A.

Thanks for mentioning that Thal!

I'm guessing the USN tables have considered the point you've made; anyway when I looked at your post and ran some imaginary dives at a "shallow-ish" depth (call 40 feet the max depth for the single dive) and the longer bottom times I'd get at that depth, it would be fairly easy to end up in USN Group-E, -F or -G... and Group-G puts you back at the DAN recommendation of 12 hours minimum...

So to the OP, strike what I said about a single very shallow dive.

 

[tfsails]

I'm a diver and a pilot. I wait 24 hours after diving before I fly. Period.

Now, I've been known to dive shortly after flying, but that's another story...

 

[diverkun]

recommend at least 18 hours for repetative dives - do you dive with a computer? If so, use it for ALL your dives during the week and plan a no fly period at least as long as the computer is telling you

also, I usually use nitrox on the last day of diving

 

[LIVES4SHARKS]

Best thing to remember is to stay conservative. I prefer to have no dives the day before I leave and fly out as late as possible. That way I have had plenty of time to offgas, rest, and hydrate well before I head home. You never know when your number is up to take a hit, so why push it?

Great posts LeadTurn and Thal!
Carolyn:shark2: