Driving to altitude after diving

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ChristyV

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# of dives
500 - 999
I live on a mountain in at 3,000 ft. By the time I get my gear off, return tanks, etc. it usually takes me a least 90 minutes to get home. If I have been to a depth of over 60 feet, or have done two dives a most shore dives seem to be, I usually take a shower and have lunch at sea level and do not head home before 3 hours have passed. If I go on a boat and dive to 100-130 feet, followed by a dive to 70 ft or less, I go get something to eat, shower, and go to my office so I can allow 4-5 hours to off gas. The drive home is a very gradual ascent from sea level to 3,000ft. I am a 58 year old woman. I do not drink any alcohol at all, keep myself well hydrated, and I am in excellent physical condition. In my "youth" (early 40's) I frequently drove home within 90 minutes of 100-120 foot dives and never experienced a problem. Am I being safe? Would I be safer if I used nitrox on all my dives? How soon can I go home? Thanks!
 
I think you're fine. Single deep dives only hit the fast tissues, so you off gas quickly also.
 
Aloha Christy:
We do it here on the Big Island all the time. Never had a problem.
Usually off gas a couple hours washing the boat down & getting lunch, then make the drive.
 
I have never really worried a lot about it but recently I was told by a dive shop that I could not make a one hour night dive to "about" 45 ft off shore with them unless I had a place to stay down there. They were pretty adamant about the "danger." I have many many times done well over an hour single dive at that beach and gotten home within two hours. Their attitude made me think I take the whole thing too lightly. P.S. I am a (non-teaching) PADI certified instructor.
 
Given your dive day description, you shouldn't have a problem. If you want to be even more conservative you could plan your dives as if you were already at altitude. For 3000ft above sea-level multiply your planned depth by 1.12 and used the altitude corrected depth to determine your dive based on the tables. Almost all my diving requires me to travel over a 7000 ft pass to/from the dive site. I've never experienced a problem.
 
...They were pretty adamant about the "danger." .... Their attitude made me think I take the whole thing too lightly. P.S. I am a (non-teaching) PADI certified instructor.

As an instructor you should know their rules have nothing to do with your safety.
Tell them whatever they want to hear. Or better yet find someone else to dive with.
 
I agree with the earlier post to plan your dives at the altitude you live. I had DM friend that got bent after doing several dives within rec limits and then drove home to just over 2,000 ft. I think that he was within 2 hours post dive when he got home, so it can happen.
 
Recently someone on Maui was "allegedly" bent after going doing a couple of dives "within recreational limits" and going to 1500 ft. You are saying he did a couple of dives within limits and was home within 2 hour, but wouldn't there be a BIG difference between going to the NDL for 130 ft, followed by the NDL for 90 ft and then going home versus doing one dive to 45-50 ft for 1 hour and being home within 2 hours. I have a lot of trouble believing that I would be in danger if I dove 32% nitrox to 45 ft for 50-60 minutes and then drove to 3000 feet within 2 hours. Listening to myself I am realizing that I want to hear what I WANT to hear so I can do what I want to do. I understand all the risk is mine. Are we all this stubborn?
 
Recently someone on Maui was "allegedly" bent after going doing a couple of dives "within recreational limits" and going to 1500 ft. You are saying he did a couple of dives within limits and was home within 2 hour, but wouldn't there be a BIG difference between going to the NDL for 130 ft, followed by the NDL for 90 ft and then going home versus doing one dive to 45-50 ft for 1 hour and being home within 2 hours. I have a lot of trouble believing that I would be in danger if I dove 32% nitrox to 45 ft for 50-60 minutes and then drove to 3000 feet within 2 hours. Listening to myself I am realizing that I want to hear what I WANT to hear so I can do what I want to do. I understand all the risk is mine. Are we all this stubborn?

There is going to be more to it than just driving to altitude. There is cardio vascular health, hydration, etc to also account for. I personally don't account for altitude when doing my dives. I live at 3600 ft and usually dive at sites at 4600 ft. Driving to those sites require traveling over a 7000 ft pass, which I typically hit within an hour of driving each direction. I typically do 3 dives a day, many of which push or exceed the NDL on the tables. From the time that I leave my home until the time that I get back is typically 12 hours. I usually leave the dive site and hit 7000 ft within 3 hours of getting out of the water. The mileage will vary, but if you have any doubts about the safety of traveling to altitude after diving, it's best to be more conservative. That's why I said that you could account for altitude during your dives and make them more conservative. Since you live at 3000 ft you could multiply 1.2 to your planned depth and that would help mitigate any potential issues. For instance if your planned depth was 70 fsw, you would multiply the time by 1.2 (70 * 1.2 = 84fsw). So instead of running the table with 70, you would use 90. If you were diving on 32% that would give you about 35 minutes of NDL at 70 fsw (instead of around 45 minutes), for your first dive of the day.
 
...but wouldn't there be a BIG difference between going to the NDL for 130 ft, followed by the NDL for 90 ft and then going home versus doing one dive to 45-50 ft for 1 hour and being home within 2 hours. I have a lot of trouble believing that I would be in danger if I dove 32% nitrox to 45 ft for 50-60 minutes and then drove to 3000 feet within 2 hours.

I got curious, so I crunched the numbers using the NOAA Dive Tables, particularly the No-Deco Air Table and the Required Surface Interval Before Ascent to Altitude after Diving table. Assuming a 1 hour surface interval between the 130/90 ft dives, both dives would put you in NOAA Group H (not necessarily any relationship to anyone else's pressure groups), and you should wait a minimum of 1:31 before ascending above 3000 ft. Doing the second profile on EAN32, you'd be a G, with no recommendation for delay before ascending to 3000 ft.
 
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