High Altitude Dives

[Red_5]

I'd like to know if the high altitude diving classes cover dives higher than 10,000' msl

there are a few locations here in CO that interest me from a historical point of view.. one location in particular is about 10,700'


this is something I would only do if I had the proper training and equipment.

 

[DA Aquamaster]

The theory is the same regardless of altitude, the issue would just be one of calculating theoretical depths for altitudes of 10,000 ft plus. As long as you get a course that teaches the math and not just a table you will be good to go.

 

[The Chad]

The altitude class I took really wasen't much, and I can't say I learned much from it. Might have been my fault, but the PADI book should give you a good idea. One thing I forgot about was that for every 1000' you go up in alt, you go up 2 pressure groups b/4 you even dive. Most computers these days figure your alt when you switch them on in the new location....just don't forget to aclaimate first. hope this helps

 

[Dive-aholic]

Like DA said, it's about working out the tables at that altitude. I did a search a few years back and found the equation for calculating theoretical depths, etc. I don't have them handy now and haven't taught Altitude in a while. I'd check Bruce Weinke's publications. He has done a lot of research on dive theory and altitude diving.

 

[8thElementDiver]

I wrote an article about it that will help with the math and your dive planning.

Be conservative, acclimate to the altitude before your dive, and understand your dive computer/depth gauge (some dive computers won't work above a certain altitude--they shut off automatically).

8th Element Diving - Scuba Math - Altitude Diving: Understanding the Tables

 

[red_barbarian]

For an extra element of margin do your calculations based on the highest altitude you'll get to on your drive home. If you are diving at 10,700 , but will then hop in the car and drive over a 12K pass run your numbers from 12k.

 

[amascuba]

Like DA said, it's about working out the tables at that altitude. I did a search a few years back and found the equation for calculating theoretical depths, etc. I don't have them handy now and haven't taught Altitude in a while. I'd check Bruce Weinke's publications. He has done a lot of research on dive theory and altitude diving.

The formula is:

1. Every 1000ft above sea-level is 4%.
2. 1.(Altitude %) x actual depth (ft) = altitude corrected depth (ft)

For example, The Blue Hole in Santa Rosa, NM. It's at 4600ft above sea-level. Round that figure up to 5000ft. Take the first rule and apply the percentage to it. 5 x 4 = 20%. The Blue Hole is roughly 84ft deep at it's deepest point near the grate. So the formula would be: 1.2 x 84 = 100.8ft. Round that number up and your altitude corrected depth is 101ft. Those number correalate with the PADI tables as well.

It should work at any altitude. You can run through the numbers quickly by using my website if you want.

SecurityGeek.Net

Scroll to the bottom and it will have a form to put numbers into.

 

[Charlie99]

The formula is:

1. Every 1000ft above sea-level is 4%.
2. 1.(Altitude %) x actual depth (ft) = altitude corrected depth (ft)

.....

It should work at any altitude.

The linear correction of 4%/1000' of altitude is reasonable for altitudes up to around 10,000'. Easy to remember. Easy to calculate. Reasonably good approximation. But it isn't intended to apply above 10,000' (although for the 10,700' site mentioned by the original poster, I'd just go ahead and use it with a tiny bit of additional conservatism).

Above 10,000' the newer models such as RGBM start getting significantly more conservative than the linearly adjusted neo-Haldanian/Buehlmann models.

RGBM altitude adjustments reduce the critical tensions exponentially as ambient pressure goes to zero. The older form of correction reduces the critical tensions linearly. IIRC, Bruce Wienke has a monograph on altitude corrections available for sale on his website in pdf form.

 

[Dive-aholic]

The formula is:

1. Every 1000ft above sea-level is 4%.
2. 1.(Altitude %) x actual depth (ft) = altitude corrected depth (ft)

For example, The Blue Hole in Santa Rosa, NM. It's at 4600ft above sea-level. Round that figure up to 5000ft. Take the first rule and apply the percentage to it. 5 x 4 = 20%. The Blue Hole is roughly 84ft deep at it's deepest point near the grate. So the formula would be: 1.2 x 84 = 100.8ft. Round that number up and your altitude corrected depth is 101ft. Those number correalate with the PADI tables as well.

It should work at any altitude. You can run through the numbers quickly by using my website if you want.

SecurityGeek.Net

Scroll to the bottom and it will have a form to put numbers into.

I actually worked out a formula that was much more specific. You could figure out the actual pressure and convert to ffw without rounding to the nearest thousand. Your 101 feet would actually be closer to 99. Not that big of a difference, but I was looking for something very specific.

 

[Stefan Austermühle]

Hi all

I am organizing a diving expedition to Lake Titicaca (3812 meters) for october 2010. If anybody is interested to join contact me

Best Stefan