Do you use your SAC for anything? POLL

[BoltSnap]

I use my SAC rate for doing vintage dives when I use no SPG. The SAC is the only way to get an idea of how much air I will need to do a dive for a certain time at a certain depth.
I also use a J valve in combination but usually I'm already back close to shore about ready to finish the dive when I need to pull the J.
Instead of looking at my pressure gauge I look at my watch and depth gauge.

How do you know if your SAC is still the same as the SAC you planned on when you were on the surface (it could have changed due to unpredicted/expected increase in exertion level U/W during the dive)?

 

[knowone]

It's not, so you practice, to get an idea, by driving around all over the place and getting home, where there are no gas stations, and if not, carry a spare can or roll to a stop by the side of the road or don't drive such a distance.

 

[BoltSnap]

It's not, so you practice, to get an idea, by driving around all over the place and getting home, where there are no gas stations and if not, carry a spare can or roll
to a stop on the side of the road or don't drive such a distance.

I thought that I was getting better in understanding you but not today it seems.

 

[kanonfodr]

SAC rate has lots of uses: pre-dive planning, mid-dive change planning, figuring out how my buddy is doing, and bragging rights to name a few.

Peace,
Greg

 

[aquaregia]

How do you know if your SAC is still the same as the SAC you planned on when you were on the surface (it could have changed due to unpredicted/expected increase in exertion level U/W during the dive)?

It's not, so you practice, to get an idea, by driving around all over the place and getting home, where there are no gas stations, and if not, carry a spare can or roll to a stop by the side of the road or don't drive such a distance.

I thought that I was getting better in understanding you but not today it seems.

Driving a car is similar. Your gas mileage can be decreased if you hit traffic or if you run the AC a whole bunch, and you might get a flat. Planning for these situations makes them non-issues. Leave larger reserves for more adventurous journeys. If you cannot make it to a gas station, carry extra gas. If you don't have roadside assistance, carry a spare.

If you exert yourself more, you'll run low on air faster, so you pull your J sooner, head to the surface and kelp crawl your way in. If the surface is not accessible in this manner, a different method should be used.

 

[BoltSnap]

Driving a car is similar. Your gas mileage can be decreased if you hit traffic or if you run the AC a whole bunch, and you might get a flat. Planning for these situations makes them non-issues. Leave larger reserves for more adventurous journeys. If you cannot make it to a gas station, carry extra gas. If you don't have roadside assistance, carry a spare.

If you exert yourself more, you'll run low on air faster, so you pull your J sooner, head to the surface and kelp crawl your way in. If the surface is not accessible in this manner, a different method should be used.

First, thank you for the translation!!

All of the "random variables" you mention are "noise/spikes" that would be rounded out in "average" calculations in the most part provided they are only "spikes/anomalies" and not the norm.

The "profiles" of the dive dictates how we handle the "averaging" (profile is not necessarily the depth profile but it is more the circumstances/variables of the dive in addition to the depth) for the dive.

BTW, it is much more efficient to run the A/C than to open the window

 

[BoltSnap]

How do you know if your SAC is still the same as the SAC you planned on when you were on the surface (it could have changed due to unpredicted/expected increase in exertion level U/W during the dive)?

aquaregia,

The quote above is directed to ZKY specifically since I am curious on how he can predicate the remaining gas in his tank without a pressure monitoring device especially when the unpredicted "spikes/anomalies" become the norm and the anticipated SAC rate is no longer accurate.

 

[knowone]

By driving the car with the A/C off windows open having removed the rear glass.

OFTEN.

Within the limits of the reserve.


By the way, your AirII post was pretty good.

 

[bowlofpetunias]

ummm....????

Oh well back on topic....

I have monitored my SAC rate over hundreds of dives in different conditions and locations. I use this information in planning dives.

IMHO people get too wound up about SAC rates! It is just a number that helps you determine what size of tank and fill level you need to conduct a specific dive safely! If you go through more air than your buddy.. :doh: get a bigger tank as long as you watch other safety factors no big deal!

 

[aquaregia]

IMHO people get too wound up about SAC rates! It is just a number that helps you determine what size of tank and fill level you need to conduct a specific dive safely! If you go through more air than your buddy.. :doh: get a bigger tank as long as you watch other safety factors no big deal!

This is something that I hear a lot. I'd like to give an alternate perspective, as an air hog. When people talk about their worst instabuddy dives, many of them involve their buddy going through a tank in an insanely short time, forcing them to cut short their expensive dive. This makes those of us with high SAC rates really focus on our SAC rates as a measure of our worth as a diver. As much as people say that it is what it is, my SAC determines the group's dive time. I did two dives today with a guy who was on his 11th dive, swam with his hands, ridiculously fast, yet used significantly less air than I did. When the standard answer to "how to lower SAC" is "get comfortable in the water", a lot of people start thinking that a high SAC indicates a bad diver.

There's a lot of times when getting a bigger tank is not feasible, not cost effective or means that your buddy wants a bigger tank too (leaving you in a similar position)