Advice to get lower SAC?

[PfcAJ]

Do a proper weight check.

15ft, near empty tank, no gas in your BC. That’s what you need to test.

Get someone to video you. I’d make a guess that you aren’t still/neutral in the water.

Dive more. Don’t be concerned with trying to save air. It’s counterproductive.

 

[fish149]

Also consider your buddy's size. I know it's hard to believe but bigger/taller people have bigger lungs and take in more air .I'm 6-02 and dive with a buddy that's about 5-05. He uses hardly any air but that's just the way things are.

 

[Mike1967]

So I have a regular dive buddy. We dive together often, and at the end of a dive, when I am hitting my return PSI, he still has way more gas than I do.

Exactly the same here and I felt badly too, I know about the don't throw gear at a problem blah blah, but I just bought bigger tanks than he has

 

[JackD342]

Probably need to question assumptions. You say another pound or two less and you can’t get down, but between your BCD and your drysuit, you might have quite a bit of buoyancy you don’t realize. So like everyone else said, do a weight check and dial in at the end of your dive with about 500 psi left. Not like you don’t ever breathe it down that far...

 

[stepfen]

Some people do have higher SAC than others - as simple as that. Mine seems to be settling to around 18lt/min.
My last hope of improving was learning frog kick and using a BPW (before I was diving crap rental BCDs). I did manage to get both over the summer and I've been using them for about 10 dives now almost exclusively but I didn't see much improvement in my SAC.
With time (i.e. more dives) my SAC is not decreasing much, but it is getting more consistent. Before I use to get values from 16 to 21lt/min or so from dive to dive. Now most of my dives are around 17-19lt/min.
Also I think that the fact I can "only" do 2 dives every second weekend or so is not helping either. I have a diving trip coming, hoping to do about 30 dives over two weeks. There, after getting used to the conditions, I hope that my SAC will settle a bit lower - but not much.
Hence to avoid the feeling of affecting your buddy's dives, my suggestions is to just use bigger tanks (if possible).

 

[clownfishsydney]

There are very many different definitions of SAC and RMV. Some say RMV is how many psi/bar are used per minute but others say the same one is how many cf or litres are used. Even in the second one, some say it is at depth but others convert it to the surface. For me, I consider them to be the same thing, that is, litres per minute surface corrected.

I presume original poster is talking of litres per minute as his example seems to fit into reality. If so, then yes they are very high. My SAC/RMV is generally about 10-11 litres per minute except on deep dives (40+ metres) when I have more gear and it is about 13.5 l/min. Most people I dive with are about 13-15 l/min, but some are the same as me and some even less. This is similar to OP's dive buddy.

The main thing about all of us is that we dive very regularly and are all very relaxed in the water. I think these two things are the most important (apart the obvious one of being overweighted).

 

[noj3333]

Other than this, if your air consumption is higher than your buddies, consider a larger cylinder. This will reduce your stress, and take the pressure off you with regards the point you turn the dive.

Get a bigger tank.

^^Local diving, this would be my 'solution'... Maybe a HP120 or 133.

 

[mi000ke]

I’ve had a pretty low RMV (around .4 or slightly less) since I first began diving, and I owe that to many years of play saxophone, where we learn to breath diaphragmatically (do a Google search and you will find lots of instruction and videos). This creates a virtuous cycle of relaxation and efficient breathing. Diaphragmatic breathing is very efficient and also creates what is often called the relaxation response, and relaxation in turn slows down your breathing. I find myself going into a "zen state" when I dive (assuming no difficult or emergency circumstances). It not only makes my gas last longer but makes the dive much more enjoyable. I shorten up my breathing as needed depending on the buoyancy issues at the moment, but when cruising along normally I'm taking slow long breathes using my diaphragm, not the "top" of my lungs, and breathing out slightly longer than breathing in (which for me is second nature, as that's what you do when playing sax). So maybe you should think about getting into playing music as well Two excellent hobbies. (And when I'm on a diving vacation I take the sax along, and I get to sit in with a lot of bands as well - makes for a great diving vacation.)

Sitting in with the band at the Marriott, Seven Mile Beach after a great day diving West Bay, Grand Cayman:

 

[scubadada]

Some people do have higher SAC than others - as simple as that. Mine seems to be settling to around 18lt/min.
My last hope of improving was learning frog kick and using a BPW (before I was diving crap rental BCDs). I did manage to get both over the summer and I've been using them for about 10 dives now almost exclusively but I didn't see much improvement in my SAC.
With time (i.e. more dives) my SAC is not decreasing much, but it is getting more consistent. Before I use to get values from 16 to 21lt/min or so from dive to dive. Now most of my dives are around 17-19lt/min.
Also I think that the fact I can "only" do 2 dives every second weekend or so is not helping either. I have a diving trip coming, hoping to do about 30 dives over two weeks. There, after getting used to the conditions, I hope that my SAC will settle a bit lower - but not much.
Hence to avoid the feeling of affecting your buddy's dives, my suggestions is to just use bigger tanks (if possible).

So, your RMV is around 0.6 cf/min, in the higher range of average. RMV in liters/min divided by 28.32 = RMV in cf/min. Less than 100 dives is still not very many dives, I would not say BP&W and frog kick were your last hopes. Keep on working on buoyancy, trim, and exertion while you accumulate more experience.

My air consumption was always pretty good but noticeably improved over time for quite a while. I did not calculate my RMV until I had over 400 dives and it has not changed all that much since, but the range has become narrower. I found that getting cold was a major determinate, perhaps even greater than exertion, of my gas consumption. Making a concerted effort to stay comfortable and warm has a positive effect on my gas consumption.

There are very many different definitions of SAC and RMV. Some say RMV is how many psi/bar are used per minute but others say the same one is how many cf or litres are used. Even in the second one, some say it is at depth but others convert it to the surface. For me, I consider them to be the same thing, that is, litres per minute surface corrected.

I presume original poster is talking of litres per minute as his example seems to fit into reality. If so, then yes they are very high. My SAC/RMV is generally about 10-11 litres per minute except on deep dives (40+ metres) when I have more gear and it is about 13.5 l/min. Most people I dive with are about 13-15 l/min, but some are the same as me and some even less. This is similar to OP's dive buddy.

The main thing about all of us is that we dive very regularly and are all very relaxed in the water. I think these two things are the most important (apart the obvious one of being overweighted).

You use the consensus definitions, SAC is generally expressed in pressure per unit time (psi or bar/min) whereas RMV is expressed in volume per unit time (cubic feet or liters/min). I use the term SRMV (surface respiratory minute volume) to ensure that it's understood I'm talking about surface corrected.

I was also unsure if the OP gave his SAC or RMV. Being from the US, I would tend to guess it was his SAC, in psi/min. That would make his RMV about 0.6-7 cf/min or 17-20 l/min, on the high side, but not terrible.

 

[Fastmarc]

As others have said, some people are just better at consuming less naturally. A lot seems to have to do with size and even gender.
My former regular dive buddy bought AL72s for his wife and daughters because it was lighter for them and they just didn't need the extra gas. Even the daughters who were at the time new and didn't dive frequently match us with psi at the end of the dive though we were using AL80s.
I seem to be one of the lucky ones. I usually have about 0.4 or less. Though I consider myself in proper trim and weighted, I still used a BCD, so not as streamlined as a BP/w.
I would say don't sweat it. It may improve or not, but worrying about it would only make it worse. It's rare for me to surface with anyone having more air than me, but I never consider it an annoyance. I'm willing to bet it isn't for your buddy as well.

Just dive and enjoy yourself.