No Fly Guidelines

[jc2]

I know the standard rule of thumb is to not fly within 24 hrs of your last dive. I did a short 35-min dive on Nitrox 32 spent about 60% of the dive at about 65 feet and the rest higher than that. My VT Pro computer had a no-fly time I think exactly 24 hours after I entered the water for the dive. So in essence, the computer just resorts to a conservative 24-hr no fly despite what your nitrogen loading is?

My other question is that I've made some adjustments to some new equipment (different length primary hose, adjusted Hog harness, etc.) I want to test the changes, do a weight check (went from a tri-lam to neoprene drysuit), and see if my mask flooding problem with my new mask on my last dive was a fit thing or I just got my hair or hood caught. I want to just do a quick dive maybe total time about 15-20 minutes at about 30-40 feet on Nitrox 32 before I head out on a dive trip. I would have about 18 hours between the check dive and the flight. I assume this is more than adequate no-fly time given I haven't been in the water in the past week.

 

[JulesVerne]

Question #1 - From what I remember, most computers have a no-fly 24h countdown, irrespective of one's real nitrogen loading stage. The reality is that I don't think (and this is my opinion) that the decompression models have been statistically tested for flying after diving so even with the computers that have a real no-fly countdown (there are a few in the market), I am not sure how reliable the information is. I think your personal judgement based on your actual dive profiles and breathing gases used, your risk profile and the DAN guidelines below are more useful to make a decision than a computer countdown.

Question #2 - see DAN recommendation http://www.diversalertnetwork.org/medical/faq/faq.asp?faqid=54
You should be OK with 18 hours

 

[Scuba Brad]

Agreed with above try a dive computer they are great.

 

[DandyDon]

I want to just do a quick dive maybe total time about 15-20 minutes at about 30-40 feet on Nitrox 32 before I head out on a dive trip. I would have about 18 hours between the check dive and the flight. I assume this is more than adequate no-fly time given I haven't been in the water in the past week.

Omg yes. The 24 hour countdown on computers is not really useful, as it applies to aggressive diving. Here's what I use:
>> Deco dives: 24 hous
>> Repetitive No Deco Dives: 18 hours, per DAN suggestions
>> Single No Deco Dive: 12 hours
>> Nitrox dive for 30 minutes to 40 feet: Is my hair dry?

 

[cerich]

I know the standard rule of thumb is to not fly within 24 hrs of your last dive. I did a short 35-min dive on Nitrox 32 spent about 60% of the dive at about 65 feet and the rest higher than that. My VT Pro computer had a no-fly time I think exactly 24 hours after I entered the water for the dive. So in essence, the computer just resorts to a conservative 24-hr no fly despite what your nitrogen loading is?

My other question is that I've made some adjustments to some new equipment (different length primary hose, adjusted Hog harness, etc.) I want to test the changes, do a weight check (went from a tri-lam to neoprene drysuit), and see if my mask flooding problem with my new mask on my last dive was a fit thing or I just got my hair or hood caught. I want to just do a quick dive maybe total time about 15-20 minutes at about 30-40 feet on Nitrox 32 before I head out on a dive trip. I would have about 18 hours between the check dive and the flight. I assume this is more than adequate no-fly time given I haven't been in the water in the past week.

I would assume you'd be fine but that is how I would judge myself. To another diver my insurance company would prefer if I made the most conservative recommendation, wait 24 hours.

 

[Damselfish]

I don't think any of the Suuntos have an arbitrary 24hr countdown, they calculate a time based on your dives.

 

[Thalassamania]

I can not make any recomendations to you, I just suggest that you research using pure oxygen to scrub out nitrogen. For example, I'm given to understand that according to a U.S. Navy Table, two hours of surface breathing pure oxygen will take you from Group N to Group A.

 

[Fastmarc]

I don't think any of the Suuntos have an arbitrary 24hr countdown, they calculate a time based on your dives.

I think this is the same with the Mares as well. The desat and no-fly times diplayed on my Nemo didn't seem to be countdown based.

 

[Charlie59]

Clearly some computers are no help with no-fly time. Some do use nitrogen load to determine no-fly time, need to check when you buy. Believe UWATEC has actual load in no-fly calc.

Or you could go with 18 hour span per DAN.

 

[Rick Inman]

The DAN (Divers Alert Network) article: http://www.diversalertnetwork.org/medical/faq/faq.asp?faqid=54