How long for air consumption to improve?

[Still Kicking]

This may have already been mentioned but new divers are naturally excited to be underwater and their heart rate is elevated, so air consumption is higher even though you are fit and have a low resting heart rate.

When your heart rate at 60 feet is the same as it is sitting on the couch watching a movie, your SAC will come down. As others said, it's all about time underwater.

 

[brsnow]

It will improve when you stop thinking about it.

 

[FreqFlier]

Trim, then weighting, then realizing hands are not propulsion.

It took my dive buddy (and my wife) about 100 dives to realize that. She's developing gills now.

 

[grantmac]

If surface swims are part of your usual dive take the opportunity to really get your heart rate down before putting a reg in your mouth an descending.

In addition to my other advice.

 

[Caversluis]

Many new divers are overweighted. This means they have to put more air in the BCD in order to stay neutrally buoyant. This increases resistance, which means higher air consumption.

There is a really simple way to check this. Take a look at your BCD at the end of a dive.

1) Beach dive: when back at the shore, do not inflate your BCD. When on the shore, look at how much air there is in your BCD. For every liter, you can take of 1 kg of weight

2) On a boat dive: ask your buddy to check your BCD before you surface. Do this at the safety stop. For every liter, you can take og 1 kg og weight.

Note: I the above, I am assuming that your surface with 50 bar. If you surface with significantly more, you need to compensate for the weight of the gas that is still in your cylinder. A normal 10L cylinder can contain 2 kg of air. So if you surface with 150 bar, there is still 1 kg of air in your cylinder, which means you should have 1L of air in your BCD.

 

[RobPNW]

Another thing I've noticed is I spend a lot more time underwater doing nothing now, lingering, hovering over the reef etc, as opposed to moving around. A lot of time, if I linger as quietly as possible (and of course using a lot less gas), I see a lot more and the sea life comes back to me. I've grown to appreciate the value in staying put and quiet in one spot and being a fly on the wall.

 

[Simondmd]

Very commonly, newer divers are a bit "diagonal" in the water. Every kick moves you forward (good) and up (often undesired). They automatically compensate for the upward thrust by being a little negatively buoyant. While that keeps them at a given depth, it burns a lot of gas unnecessarily.

Get a buddy to video you or even just mirror your orientation with their arm for feedback. If you're diagonal, then shifting weight is an easy fix that will improve your consumption.

A more subtle issue is that someone might be horizontal & neutral, but they have to keep kicking to stay that way. If they stop kicking, they rotate (typically feet sink). By improving weight distribution, they can be horizontal or angled as they desire (e.g., to look under a ledge) without the need to constantly kick.

This is really helpful thx. I have just come back first dive trip in a while and was using more air than my newly certified kids. I relate to the diagonal situation you describe. Could you explain more on shifting weight to fix this? Are you saying there is a way to get weight further up your body than where the belt typically sits around your waist? I was also finding a tendency to 'roll', so moved weights further round towards my front which fixed that.

 

[NothingClever]

@Wheeler925

Lots of great advice here.

Pick one thing to work on during each dive (like “no hand swimming” and then later “belly breathe”) and you’ll start seeing improvements. Don’t expect to implement everything here at once.

Pretty soon you’ll have a new frustration - having tons of air and ABT remaining at the charter’s end-of-dive time (usually 50 minutes).

Keep going. You got this.

 

[inquis]

I relate to the diagonal situation you describe. Could you explain more on shifting weight to fix this?

Putting some of your required weight in a couple of trim pockets on the upper tank band usually works well. (Push them as close as you can toward your back to minimizing rolling.)

For example, I need 10 lbs in salt water w/ 3mm wetsuit to be neutral with minimal air in an AL80 tank and my BC. By putting 2 lb in each trim pocket and 3 lb in each waist pocket, I am balanced. I don't rotate when I stop kicking, and can tip up or down by extending arms or legs.

 

[Simondmd]

Putting some of your required weight in a couple of trim pockets on the upper tank band usually works well. (Push them as close as you can toward your back to minimizing rolling.)

For example, I need 10 lbs in salt water w/ 3mm wetsuit to be neutral with minimal air in an AL80 tank and my BC. By putting 2 lb in each trim pocket and 3 lb in each waist pocket, I am balanced. I don't rotate when I stop kicking, and can tip up or down by extending arms or legs.

Thank you so much - I think this will improve things a lot for me