Flying @ 1500 ft after shallow dives

[HKGuns]

Thanks for the follow-up. Glad you made it. Based on the depths and flight, sounds like these may have been Manitou Island wrecks?

 

[duke dive medicine]

Haha. OP here, not wanting to keep y’all in suspense, but still on the road here.

I feel perfectly fine and normal.

Details: 2 freshwater Lake Michigan wreck dives. first in like 3 meters, < 30 min dive, not much to see. SI about 30 minutes. Second, about 8 meters, 45 minutes. Again limited just by what there was to see on the wreck.

15 min flight began about 2.5 hours after end of second dive. Pilot aware of situation and promised to keep altitude < 2000 feet, and didn’t let me know otherwise afterwards, but I didn’t press him for actual max.

I’ll review this thread in detail later and probably have more to say in reply. But thanks in advance for all the input.

A day late here, but for posterity, according to the US Navy Diving Manual, you could have spent all 75 minutes on air at 8 meters, come out as a US Navy RGD of F, and safely ascended to 5000'/1524 m of altitude immediately after. Standard caveats apply, i.e. use these at your own risk and remember that they were designed for fit, medically screened US Navy divers.

The whole US Navy Diving Manual is available for download on the Navy's Supervisor of Salvage (SUPSALV) website: Naval Sea Systems Command > Home > SUPSALV > 00C3 Diving > Diving Publications

Best regards,
DDM

 

[Superlyte27]

So, I flew to west palm beach for both days of mini season and immediately (within an hour) flew home. I did two dives with 20 minutes of deco each day.

For an answer to these questions, consult the navy dive manual and you’ll see that the answer to your question is, that you’ll be just fine.

 

[rsingler]

So, I flew to west palm beach for both days of mini season and immediately (within an hour) flew home. I did two dives with 20 minutes of deco each day.

For an answer to these questions, consult the navy dive manual and you’ll see that the answer to your question is, that you’ll be just fine.

Need some context.

Dive profile? Check: something with 20 min of deco.
SI?: Check: <=1 hour
Altitude of flight? : ??

20 min of deco could put you in a repetitive group anywhere from K to O. I don't see any allowable surface interval less than an hour for a flight to 2000 ft, much less airliner cabin altitude, for those repetitive groups.
U.S. Navy Diving Manual, Change 7
pages 9-62 ~ 9‐82

 

[Superlyte27]

120’ dive 20 min of deco on 32%. Square profile. Flight 3000’ or less

surface interval between dives was 40 min.

 

[boulderjohn]

When I dived Saba, they told us emphatically that the tule was exactly what I had heard when I asked DAN about it--you can ascend 2,000 feet pretty much right away. We were told the planes would not exceed that altitude. I sat behind the pilot and could clearly see the altimeter--2500 feet.

 

[rsingler]

120’ dive 20 min of deco on 32%. Square profile. Flight 3000’ or less

surface interval between dives was 40 min.

Help me find where the Navy Tables give you a repetitive group for EAN32 deco. I can see where accelerated deco on nitrox might put you in an acceptable repetitive group for flight to altitude. I just can't find it.

 

[Superlyte27]

Look at 9-53

 

[Asteve]

Could you not just set your computer to diving at 2000 ft and not go into dec.and then you would be able to fly right out of the water?

 

[boulderjohn]

Could you not just set your computer to diving at 2000 ft and not go into dec.and then you would be able to fly right out of the water?

Diving with the computer set to 2,000 feet (which many computers cannot do) will give you slightly shorter NDLs. According to the US Navy tables, if I did a 45 foot dive for 125 minutes, I would be in pressure group N and would have to wait 5:32 before ascending 2,000 feet. I can't be perfectly sure, but let's say that I cut that time a little short because I had a computer set to 2,000 feet altitude. In that case, I would be in pressure group M, and I would have to wait 4:28 before I could ascend to 2,000 feet.

When we have discussions on ascent to altitude discussions, many people advocate setting the computer to the altitude of the coming ascent and thinking this clears them to ascend to that altitude. I have no idea where that belief started, but it is quite common. I have never seen it even mentioned in any resource on altitude diving.