Using the dive log data on DiveBuddy (over 3000 logged dives), I just figured out the average depth and time for most scuba divers...54 feet for 52 minutes. That’s using a standard AL 80 cu/ft tank (3000 psi).
To develop a baseline using this average, we can do something like this (figures are rounded)...
Time (Depth/33) = ?
52 (54/33) = 85
To make this average depth and time the baseline for all other calculations, we can set it to 100...
100 - 85 = 15 (15 will now be a constant used in the equation)
So using my three dives listed above, the calculations would look like this:
1. 60 (40/33) = 73 ... + 15 = 88 (88 is lower than 100, so on this dive, I didn’t breath as good as the average scuba diver).
2. 45 (60/33) = 82 ... + 15 = 97 (97 is pretty close to 100, so I did pretty good on this dive).
3. 25 (90/33) = 68 ... + 15 = 83 (83 is lower than 100, so I need to work on my breathing).
Here’s another sample, lets say I dove to 50 feet for 65 minutes...
4. 65 (50/33) = 98 ... + 15 = 113 (113 is a lot better than 100, so my breathing rate was awesome on that dive).
So the final simple calculation to determine my underwater breathing rate, only using depth and time, compared with the average scuba diver, with 100 as the baseline, would look like:
Breathing Rate = (Time (Depth/33)) + 15
Any number around 100 is average. Any number above 100 means you breath better than most scuba divers. Any number below 100 means you need to work on your breathing.
What do you think?