Average Gas Consumption

[scubadada]

New information. My last dive averaged a fairly shallow 32 feet in a drysuit. The calculated consumption was below .8. So, either that's progress or it was just a shallow dive.

RMV is depth independent, it's at 1 atm.

 

[scubadada]

More than 70,000 views and 847 votes in the poll

The median, mode, and weighted average remain 0.5-0.59 cu ft/min or 14.2-16.9 l/min.

If you have not voted in the poll, please consider doing so. If your average RMV has changed, please change your vote.

Great diving to all

 

[WillieJustice]

It dropped a hair last dive. Below 0.9 even diving in a drysuit. It was a comfortable, low speed dive looking at a whole lot of micro-fauna. So, progress.

 

[scubadada]

More than 71,000 views and 853 votes in the poll

The median, mode, and weighted average remain 0.5-0.59 cu ft/min or 14.2-16.9 l/min.

If you have not voted in the poll, please consider doing so. If your average RMV has changed, please change your vote.

Best wishes for your diving.

 

[Sascha314]

I am actually not sure what to pick. Still in semi-dry or wet.

On a good day with watertemps > 14°C and depending on the dive profile it can get as low as 12 to 13.5 l/min. However if I have < 10°C for a non negligible time it can go up to 15 ot even almost 17l/min (if there is also some faster kicking involved).
So its between two options

 

[scubadada]

I am actually not sure what to pick. Still in semi-dry or wet.

On a good day with watertemps > 14°C and depending on the dive profile it can get as low as 12 to 13.5 l/min. However if I have < 10°C for a non negligible time it can go up to 15 ot even almost 17l/min (if there is also some faster kicking involved).
So its between two options

I generally tell people to take their average over a large number of dives, representing their average RMV over the variety of circumstances they dive. My average RMV is over a few more than 1,950 dives.

It is very clear to me that exertion, being cold, and anxiety all increase my RMV. My highest gas consumption was on the stern of the Chester Poling out of Cape Ann, MA. It was cold (47F, 8C), dark, and brisk current in a 7 mm full suit and 5/3 mm hooded vest. My RMV was 75% above my average.

 

[jborg]

This (gas consumption) feels like something that, in a sufficiently large population, should follow a normal distribution/curve. The poll answers are quite left-skewed though, leading me to believe that some data points that should be in the middle have been tweaked slightly to end up a step to the left...

 

[Sascha314]

This (gas consumption) feels like something that, in a sufficiently large population, should follow a normal distribution/curve. The poll answers are quite left-skewed though, leading me to believe that some data points that should be in the middle have been tweaked slightly to end up a step to the left...

While I believe this is true to some extend, there is also the effect of smaller sample size PLUS a distribution, which has a lower limit "0". Then you would expect rather a Poisson distribution, as the data also suggests at least from a visible glance.

@scubadada
Need to do the math for averaging it for the individual dives.

 

[scubadada]

This (gas consumption) feels like something that, in a sufficiently large population, should follow a normal distribution/curve. The poll answers are quite left-skewed though, leading me to believe that some data points that should be in the middle have been tweaked slightly to end up a step to the left...

When I started this thread and poll nearly 8 1/2 years ago, I made the poll anonymous and allowed people to change their vote if need be. I have always hoped that voters would be honest and use reasonably good data, best I could do. I'm not surprised that the curve ends with a cliff at <0.3 cu ft/min or 8.5 L/min as the physiologic minimum is probably somewhere not far below that

 

[Divin'Papaw]

When I started this thread and poll nearly 8 1/2 years ago, I made the poll anonymous and allowed people to change their vote if need be. I have always hoped that voters would be honest and use reasonably good data, best I could do. I'm not surprised that the curve ends with a cliff at <0.3 cu ft/min or 8.5 L/min as the physiologic minimum is probably somewhere not far below that

Given that it is anonymous, I have no clue why someone would fabricate their results. I believe you may also be seeing the fact that ScubaBoard has a much higher percentage of very active divers than the diving community as a whole.