Average Gas Consumption

What is your average RMV?

  • less than 0.3 cu ft/min, 8.5 l/min

    Votes: 12 1.4%
  • 0.3-0.39 cu ft/min, 8.5-11.2 l/min

    Votes: 99 11.7%
  • 0.4-0.49 cu ft/min, 11.3-14.1 l/min

    Votes: 226 26.7%
  • 0.5-0.59 cu ft/min, 14.2-16.9 l/min

    Votes: 254 30.0%
  • 0.6-0.69 cu ft/min, 17.0-19.7 l/min

    Votes: 125 14.7%
  • 0.7-0.79 cu ft/min, 19.8-22.5 l/min

    Votes: 88 10.4%
  • 0.8-0.89 cu ft/min, 22.6-25.4 l/min

    Votes: 18 2.1%
  • 0.9-0.99 cu ft/min, 25.5-28.2 l/min

    Votes: 11 1.3%
  • greater than or equal to 1.0 cu ft/min, 28.3 l/min

    Votes: 15 1.8%

  • Total voters
    848

Please register or login

Welcome to ScubaBoard, the world's largest scuba diving community. Registration is not required to read the forums, but we encourage you to join. Joining has its benefits and enables you to participate in the discussions.

Benefits of registering include

  • Ability to post and comment on topics and discussions.
  • A Free photo gallery to share your dive photos with the world.
  • You can make this box go away

Joining is quick and easy. Log in or Register now!

The 75F (24C) at 114.5’ (35m) deep dive’s excitement of watching the Galapagos Shark parade was sure messed up my RMV. LOL :wink:
Well, I reviewed my Shearwater iCloud logbook to see the data for that deep dive. Actually it wasn’t messing up that badly. May be because we were just hanging still on the bottom, relaxing & enjoying the show. My SAC was 9 psi/min at 115.9’ depth, as shown, below.
52ED8D25-856F-4E6C-AA6F-7CFCB41A26B5.jpeg


The average SAC was 12.67 psi/min, as shown, below. I think the yoyo diving (from 60’ down to 80’, up to 60’, down to 80’, up to 50’, down to 70’), when was in the middle of schooling fishes (snapper, bonito tuna, bigeye jack) before the slow ascent to the surface, messing up my SAC.

0DA23EEE-A8FF-4D14-A873-815C105083C0.jpeg
1D0413B5-57A5-4243-B0F2-DEFD93054CE1.jpeg
0CEFCA3F-77A9-4413-B956-C87003632A11.jpeg
 
You must be one of the 5 divers who voted less than 0.3 cu ft/min in the poll. Six to 8 L/min would be 0.21-0.28 cu ft/min. The lower part of that range appears to be pushing the lower limit for RMV Average Gas Consumption

Maybe it's the lazy dives we do in those tropical waters that lead to good sac rates. I do a lot of dives where we simply drift with the currents. Also the places I dive the guides are also excellent on air some are better than I am yet they never concern themselves with knowing their sac rate. Mostly I would be in the 8l min range on most dives.

A SAC WRECK DIVE.jpg

A JUN JUN BDC.jpg
 
Maybe it's the lazy dives we do in those tropical waters that lead to good sac rates. I do a lot of dives where we simply drift with the currents. Also the places I dive the guides are also excellent on air some are better than I am yet they never concern themselves with knowing their sac rate. Mostly I would be in the 8l min range on most dives.

View attachment 673381
View attachment 673385
My 9 psi/min SAC in the above post at the bottom (35 msw) motionless, while watching the Shark parade is equivalent to 8 L/min RMV.
 
Sometimes, the diving is very easy...

Over the last 1,654 dives, my average RMV is 0.36 +/- 0.04 cu ft/min (mean +/- std dev). I recently returned from a two week trip to Bonaire with my wife, where I did 45 dives Trip Report - Bonaire: Den Laman and Dive Friends, October 20-November 3, 2021. My average RMV was 0.32 +/- 0.03 cu ft/min. The water was warm, 83-5 degrees, the visibility was good, 50-100 feet, and there was generally little to no current.

I had my lowest RMV ever, more than 2 std dev below my average:
1638797505483.png
1638797522366.png


Last June, I did 19 dives in Jupiter, West Palm, and Boynton Beach Trip Report - Back in SE FL 2021 part 4. My RMV was 0.38 +/- 0.03 cu ft/min. Water temperature was as low as 60 degrees. Visibility was as low as 15-20 feet and there was very brisk current on several dives.

My RMV was as high as 0.44 cu ft/min, 2 std dev above my average:
1638800239893.png
1638800263460.png


So, sometimes the diving is easy, doesn't get much easier than in beautiful Bonaire :)
 
This, nearly 5 1/2 year old thread, continues to be quite active, with 22,350 views now. There have been an additional 14 votes in the 2016 poll over the last month. Vote in the poll, if you have not done so. Change your vote in the poll if your average RMV has changed since you last voted.

1639752986312.png
1639753006592.png


The median and the mode in the 2016 poll are 0.5-0.59 cu ft/min. The weighted average is also in the mid 0.5s cu ft/min. Fifty six percent of divers in the 2016 poll have an average RMV of 0.4-0.59 cu ft/min
 
Just discovered this great thread despite years of lurking on SB before joining. Will vote soon - haven't yet because I went cross-eyed looking at numbers in cu ft/min.

I found the discussion around the RMV/temperature interesting (and a little bit entertaining). Eyballing the posted scatterplots, I would be very dubious of interpreting the plotted line as a regression line. In other words, they can be fun to speculate, but a bad idea to think the data supports any prediction about RMV, given the temperature, or vice versa, or worse that it provides information to use for dive planning. This is especially true because a simple scaling of the axes will dramatically change their appearance.

I think this sums up perfectly how to approach the data:
Regardless, I have fun looking at my dive data when I am not lucky enough to be diving :)
 
https://www.shearwater.com/products/swift/

Back
Top Bottom