GOOD ADVISE FROM DAN - RE: SURFACE ALTITUDE and FLYING

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Rambo2

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I am fairly new here but I just love the forums and the member posts. Talk about TOUGH LOVE :bash: :cheers:

I will be going to Kona next month and the Mauna Kea observatories are one of my favorite places on the planet. The following is a question to DAN and their response. I thought it was worth sharing.

Original question:
I will be diving in Kona, HI in November. I am also planning to visit the observatories at Mauna Kea. The elevation at the visitor center is 9000' and the summit is at 14,000. What precautions would you recommend after diving. Is this the same as flying or more serious?
Thank you

from reply
"Regarding driving/climbing to altitudes after diving, a point to remember is that airplane cabin pressures are maintained between 2,000 and 8,000 feet even if the plane’s cruising altitude is higher. So while cruising at 30,000 feet, the cabin pressure does not exceed 8,000 feet. From a pressure standpoint:
• surface pressure = 1.0 atm
• 8,000 feet decreases pressure to approximately 0.71 atm (cabin pressure)
• 9,000 feet = 0.68 atm (Mauna Kea visitor center)
• 14,000 feet = 0.54 atm (Mauna Kea summit)"

Full Reply
David,

Thank you for contacting Medical Services of Divers Alert Network, and your commitment to dive safety. There are dive destinations that offer divers a variety of environments below and above the water. Divers can literally perform a series of dives in the morning, then in the afternoon visit the crater of a volcano. Most divers would not even think about boarding a plane sooner that the recommended wait-to-fly time. They don’t always recognize that driving to the crater of that volcano that takes them to 10,000 feet is the same as flying after diving. Physiologically there is no difference. Sometimes too, divers have to drive through a mountain pass that is higher than 2,000 feet to get to their intended dive site. They will have to drive back through the same pass after diving. The bottom line is to remember that altitude exposures are altitude exposures regardless of how you get there.

Regarding driving/climbing to altitudes after diving, a point to remember is that airplane cabin pressures are maintained between 2,000 and 8,000 feet even if the plane’s cruising altitude is higher. So while cruising at 30,000 feet, the cabin pressure does not exceed 8,000 feet. From a pressure standpoint:
• surface pressure = 1.0 atm
• 8,000 feet decreases pressure to approximately 0.71 atm (cabin pressure)
• 9,000 feet = 0.68 atm (Mauna Kea visitor center)
• 14,000 feet = 0.54 atm (Mauna Kea summit)

So the Mauna Kea visitor center has a relative pressure just slightly less than a commercial airliner, and the summit is a little over half of surface pressure. The generally recommended guideline is a surface interval of 18-24 hours from last dive to flying, and climbing to altitude should be treated in a similar fashion. With the reduction in pressure at summit, a suggested wait of 24 hours would not be unreasonable. Allowing more than minimum waiting time before and after diving may help you enjoy diving for many more years without incident.

Most importantly the guidelines apply to divers that have no symptoms. If there is any doubt as to whether or not a diver has symptoms they should be evaluated by a local dive physician before altitude changes, whether flying or climbing a mountain.

The following guidelines, which apply to commercial aircraft, provide divers with the option of reducing the waiting time after certain diving schedules. However, divers are still advised to wait at least 24 hours, if possible.

• A single dive within recreational no-stop limits 12 hours
• Multiple days/multiple recreational dives 18 hours
• Decompression diving (planned or unplanned) 24 - 48 hours

Please note these guidelines are not infallible. A substantial number of divers have suffered from bends after having waited longer than 24 hours before flying. Some divers have experienced symptoms even after waiting 48 hours to fly after extensive diving.

Frances


Frances Smith
DAN Medical Services
Divers Alert Network
6 W Colony Place
Durham, NC 27705
USA

919-684-2948 x 237
800-446-2671 x 237
FAX: 919-493-3040
 
You've quoted it, but do you understand it?
The short answer to your question is, "Don't do it."
Visit Mauna Kea *before* you start diving, not during or right afterwards.
And on Maui don't visit Haleakala, either!
 
Thanks for posting . As tursiops said , "Dont do it ."
Have a great time . Hawaii is a wonderful place .
 

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