How to reduce a monstrous SAC

[halocline]

If you use an Air-Integrated dive computer with a heart rate monitor on every dive like we do with our students, then you can download your computer after every dive and analyze your breathing, heart rate and workload.

The Scubapro Galileo Sol is the computer....

Also, I would recommend that you dive with two independant tanks, 2 80 cuft or 2 63 cuft. tanks. That way you will not be "the Guy" that is low on nitrox and is the first to end the dive.

By having two independent systems, you'll have redundancy.

Make sense?

Sure, it makes perfect sense to address a moderate air consumption issue by buying a $1500 computer and carry an entire extra tank around...

Another bit of useful advice from a dedicated dive professional. :bs:

 

[GrumpyOldGuy]

If you buddy dive and your buddy has an unstressed SAC of 0.75 cuft/min (like the OP), then it would be easy to argue that your current rock bottom calculations aren't conservative enough.

Good point, I provided an overly simplistic answer. I used a spreadsheet (downloaded from SB) to plan gas use for the dive and calculate rock bottom. It contains fields for unstressed rate (for the dive) and stressed rate (for the ascent w/buddy). For an unknown buddy, I plan .75 unstressed and 1.25 stressed. The point being .75 is at the high end of reasonable gas use, not the end of the world. I use unstressed SAC of .4 for myself with a stressed rate of .75

 

[beaverdivers]

Sure, it makes perfect sense to address a moderate air consumption issue by buying a $1500 computer and carry an entire extra tank around...

Another bit of useful advice from a dedicated dive professional. :bs:

Nice Flag!

Here's a recent qoute from one of my clients that has similar gas consumption as the OP.

"We had a very hard, against the current swim at 75 feet in Cancun and learned to appreciate the quality of our MK25/S600 flow delivery.

One other diver in our group had to stop swimming as he exceeded his regulator’s ability to deliver air to match his workload.

We were fine.

We all stopped and surfaced at that point as the current had reversed and we couldn’t get to the second part of the wreck.

Good to have 80 x 2 air tanks.

Not sure Mike will ever dive without dual 80’s again."

Why would you want to send a diver down with inadequate equipment and not enough gas?

 

[TSandM]

Beaverdivers, I'm totally with you on this one . . . the dives we did in West Palm Beach, for example, were square profile dives with depths between 80 and 100 feet, for the most part, and were perfect for double 80s (although I don't dive independent doubles). The rock bottom reserve on a single 80 for such a dive makes for a very short bottom time.

I'm also a believer in using a larger tank, if you find your gas consumption is limiting your diving. But most people aren't going to want to dive doubles -- they are very heavy, and have to be configured so they ride well, either on your back or in a sidemount configuration. Diving a single back-mounted tank and a slung 80 isn't really very comfortable, at least for me, and I wouldn't generally recommend doing it.

 

[halocline]

Why would you want to send a diver down with inadequate equipment and not enough gas?

If you think that recreational diving without a $1500 computer and independent doubles (exactly what you recommend to the OP) is 'inadequate' then you're truly delusional. How on earth have the many many thousands of divers that routinely dive recreationally with a single tank and without the galileo sol ever survived? How could they possibly enjoy diving with such inadequate gear?

Look, the reason I object to your "suggestions" is because they are nothing more than sales pitches for gear that you sell. You even managed to turn this thread into a sales pitch for the MK25/S600, even though it has ZERO to do with the topic. And BTW, in case someone gets fooled by the nice exciting story told by beaverdivers, the limiting factor in ANY decent scuba regulator for air flow is the tank valve.

Amazing...

 

[beaverdivers]

It is ONLY a problem for many poor guys like my friend & the OP.

 

[RonFrank]

I dove Boynton (flat deep FL profile at 80-100ft) with a HP100 32% and hit NDL. You do not need doubles just a reasonable SAC. But so what if you can not squeeze every minute out of a dive. Most divers recognize this as a deepish dive and perfect air usage is not a requirement. As long as everyone is safe and has fun.

To the OP, I have a good buddy 6'4", big guy. His SAC did improve over time but he got a couple AL100's. Sometimes the solution is bigger tanks for bigger lungs! He can usually rent 100's as well.

 

[Centrals]

Here's a recent qoute from one of my clients that has similar gas consumption as the OP.

"We had a very hard, against the current swim at 75 feet in Cancun and learned to appreciate the quality of our MK25/S600 flow delivery.

One other diver in our group had to stop swimming as he exceeded his regulator’s ability to deliver air to match his workload.

We were fine.


Why would you want to send a diver down with inadequate equipment and not enough gas?

The other diver was probably also using ScubaPro equipment, was he?
The inadequate equipment probably include MK17, 11 and 2 etc etc as well.

I DO NOT need a computer to tell me that I am over-work!! I know my limit and will take the necessary action.
I would rather spend US$1,500.00 on helium than a piece of electronic which serve no purpose whatsoever for me. Dive plan on slate and two bottom timers are as good as anything for me.

As for the original question: I wont' worry too much on high SAC. Just ask for a bigger tank on you next dive. Improvement will come eventually and in the mean time enjoy the fun.

 

[beaverdivers]

The other diver was just another diver on the boat using rental gear. It was poor quality rental gear!

 

[aquaregia]

The other diver was just another diver on the boat using rental gear. It was poor quality rental gear!

Probably just poorly serviced.

To remain on topic: 5'11", 200lb, 200 dives, SAC=0.5 drift, 0.75 cold water, 1.1 stressed. I fence and occasionally run half-marathons (poorly). The "don't worry about it" excuse doesn't cut it when your buddies keep hounding you to spend hundreds of dollars on bigger tanks so they can dive longer.