How Long Should I Wait Before Driving Up To 6000ft?

[GrumpyOldGuy]

I ran the numbers from NOAA tables a year or so ago. On Maui it is possible to get hurt driving up to the top of the volcano (10,000ft) after several deep dives. I also know some local Colorado divers actually did get bent driving back from Rock Lake in Santa Rosa New Mexico last year. So U should not dismiss the question. Do the numbers.

 

[LeadTurn_SD]

I ran the numbers from NOAA tables a year or so ago. On Maui it is possible to get hurt driving up to the top of the volcano (10,000ft) after several deep dives. I also know some local Colorado divers actually did get bent driving back from Rock Lake in Santa Rosa New Mexico last year. So U should not dismiss the question. Do the numbers.

On the Big Island as well. Depending on which road I take, if I drive from Hilo to Kona to dive, there can be a fairly rapid and significant altitude change. I do typically remain at sea level 3-5 hours after my last dive before driving home to Hilo on the "lower" highways, and avoid Saddle Road after diving.

The USN Tables (and NOAA) have some guidance and tables regarding ascent to altitude after diving... which is where I originally came up with the times I use before driving to altitude here.

I'm far from an expert, but do know (and know of) divers who have reported bends or suspected bends from driving to altitude too soon after long dives.

Use good judgement and be safe.

Best wishes.

 

[theduckguru]

Lamont, re-read the OP's first post. Asking about driving to altitude.

I can understand the need for the conservatism if flying. Even though you may be out of the water for a few hours before takeoff (assuming the worst disciplined diver), it only takes seconds for that plane to climb above the 7000 foot mark that the cabin is pressurized to. If you take the chance of catastrophic pressure loss, then you would instantly jump from 7000 to 35,000 foot in pressure. That is serious concern for DCS.

While your concern is valid, you can get bent with a rapid pressure loss in an aircraft above 23,000 even if you have never made a scuba dive in your life.


www.faa.gov/pilots/safety/pilotsafetybrochures/media/dcs.pdf

I'd wait at least 12 hours, which is the FAA's minimum reccomendation for a non deco dive and a flight lower than 8000 ft.

===============================================================

d. Decompression Sickness After Scuba Diving.

1. A pilot or passenger who intends to fly after scuba diving should allow the body sufficient time to rid itself of excess nitrogen absorbed during diving. If not, decompression sickness due to evolved gas can occur during exposure to low altitude and create a serious inflight emergency.

2. The recommended waiting time before going to flight altitudes of up to 8,000 feet is at least 12 hours after diving which has not required controlled ascent (nondecompression stop diving), and at least 24 hours after diving which has required controlled ascent (decompression stop diving). The waiting time before going to flight altitudes above 8,000 feet should be at least 24 hours after any SCUBA dive. These recommended altitudes are actual flight altitudes above mean sea level (AMSL) and not pressurized cabin altitudes. This takes into consideration the risk of decompression of the aircraft during flight.

 

[--tom--]

I ran the numbers from NOAA tables a year or so ago. On Maui it is possible to get hurt driving up to the top of the volcano (10,000ft) after several deep dives. I also know some local Colorado divers actually did get bent driving back from Rock Lake in Santa Rosa New Mexico last year. So U should not dismiss the question. Do the numbers.

If you think deep dives and altitude is risky, run the numbers for very long moderate depth dives and altitude, e.g. (3) 70 minute dives with 1 hour SI @ 40'. The off-gassing time is a lot longer.

 

[theduckguru]

After 12 hours SI, everyone is an Alpha.

 

[TSandM]

Well, it may be true that after 12 hours, everyone is an A, but remember that the pressure groups are based on a selected compartment. Almost all tables largely ignore the long half-life compartments, because they simply don't impact single day diving. They may have significantly more impact after multiple days of multiple dives. To my knowledge, there aren't really a lot of good studies of flying after a week of doing four or five dives a day -- BUT there are statistics that tell us that the majority of the DCS cases off liveaboards occur at the beginning of the trip. Which may argue that the limits we are espousing for people at the end of such trips may be overly conservative. There are no good data to say, one way or another.

I have personally concluded that, for a single day of diving, if I do the deco I was taught to do, I do not worry about driving to altitude afterwards. I simply cannot get there fast enough to get into trouble.

 

[ZenDiver.3D]

After multiple days of repetitive dives, simply err on the side of caution, and wait a day before driving over the mountain. Play the odds, or wait 24 hours. It's your call, but why not be careful and enjoy a day of play before driving?

 

[Seaduced]

This is purely anecdotal. My wife and I drive back from San Carlos, Mexico after diving, reaching about 4500' near Nogales. This is the weekend dive trip plan, for longer periods, we don't dive on the drive day. When I set up about our 'Drive Day Dive' procedure, I used 5000', a change of about 2.5 psi from sea level. That's equivalent to about 5' in water. That change in altitude is spread over more than 2 hours of driving, so the rate is not an issue.

The day before we drive, all the dives are 60' or less, usually 40'. We brief, "keep it shallow." The day we drive, we shore dive in a small cove, no current and about 25' depth, so exertion is minimal and slow compartments minimally on gas. It takes 2-3 hours to load up, drive back to our place, clean gear, shower and pack the truck. With a 5-6 drive to Nogales, after about 8 hours we reach the highest altitude. We have never had an issue, at least none that we recognized. If there was ever a reason for concern, we'll wait another day before driving back.

With the airliner cabins being 6000-8000', leaving from a near sea level airport, nearly every passenger would get bent, if that change was an issue. Isn't the real danger loss of cabin pressure, and the rapid further 8 psi drop? When there is a loss of cabin pressure, don't some passengers get bent anyway? For an off-gassing diver it could be very serious.

 

[LeadTurn_SD]

I just don't have enough knowledge to comment other than "what I've been told"... I have read of bends cases after flying on a commerial airliner post-diving; I've "heard" of bends cases induced here in Hawaii by driving to altitude post-diving.

If I dive in Hilo or Kona, I can theoretically jump in the car at be just shy of 7,000 feet (Saddle Road) while my hair is still wet from the dive, or at just under 3,000 feet (Waimea) or 4,000 feet (Volcano National Park).

Now, for any given dive I just don't know what the real risk is, but based on "what I've heard" regarding actual cases of divers getting bent after driving to altitude here in Hawaii, I would not completely dismiss the possibility that there is some degree of risk. I think that the longer the surface interval you have prior to the drive, the lower the risk, and at a certain point the risk is "gone". Since I don't really understand where the "no risk" point is, I refer to the USN "Ascent to Altitude" table when considering driving right after diving.

Best wishes.

 

[scubadada]

Hi guys,

I did some search on the forum regarding driving after diving but i'm still confused. There are numerous techniques mentioned, but what I would like to know is after doing multiple dives for three (3) days, how long would I need to wait before I drive to a town with an elevation of 6000ft? I'm not sure if it relates, but PADI recommends not less than 18 hours after doing multiple day dives before taking a flight...

This is funny, I read the title and thought this was diving, not driving, to 6,000 feet. This would have been a one upsmanship to the piddling 85 meter dive discussed in this forum. There's a lot of humor on SB, some of it you just have to create for yourself.

Good diving, Craig