Altitude Diving

I'm sure this question has been asked and answered before, but what changes to the NDL tables do I need to make for altitude diving in a lake at approx. 3400 ft.? I have always been a salt water diver, but we are going camping in the mountains in a couple of weeks and I thought it might be fun to plan a couple of dives in the lake we are camping on (Bumping Lake, WA., just on the east side of Naches Pass, Mt. Rainer). My son and I will plan conservative dives (60 ft. or less), and I run a UWATEC Smartcom and he has a Cressi Archamedes. Do either of these computers compensate for altitude? I appreciate any info. or personal experiences at mountain lake diving.

I ignore the differences

It's customary to add 4% for each 1000ft of elevation to your depth.

The Smart Com automatically compensates, I don't know about the Cressi.

Here is a couple of links that might help you out:

http://www.blowinbubbles.com/scubalti.htm

http://www.mermaidscuba.com/altitude.shtml

Please be aware that there are other considerations than just theoretical depth conversions, like different safety stop depths for different altitudes, accounting for the time you have been 'at altitude' and planning your first dive as a repetitive dive, accounting for mountain passes you have crossed....

I'm not one of those guys who always replies with, "take the class," but I would certainly recommend that you get a proper education on all the aspects of diving at altitude, whether it is from a good instructor or personal research. I don't think a short answer on SB will cover all the considerations.

Actually, I would recommend a good instructor and personal research. I had a good LDS for my altitude class, but the instructor still gave bad info that I wouldn't have recognized as such if I hadn't done my own reading.

Do what you want, but please look into all the aspects, not just the depth conversion.

Dogboy:

I'm sure this question has been asked and answered before, but what changes to the NDL tables do I need to make for altitude diving in a lake at approx. 3400 ft.? I have always been a salt water diver, but we are going camping in the mountains in a couple of weeks and I thought it might be fun to plan a couple of dives in the lake we are camping on (Bumping Lake, WA., just on the east side of Naches Pass, Mt. Rainer). My son and I will plan conservative dives (60 ft. or less), and I run a UWATEC Smartcom and he has a Cressi Archamedes. Do either of these computers compensate for altitude? I appreciate any info. or personal experiences at mountain lake diving.

Click to expand...

You will find a lot of info in this thread...
http://www.scubaboard.com/showthread.php?t=98368&highlight=altitude