What's a good SAC

[Storker]

After several years of diving (about 32) and based on my PERSONAL preferences, I just can't understand why ANYONE would dive in cold dark water.

Well, for some of us it's either diving in cold dark water or not diving at all.

With the right gear, the right mindset and the right skills, it can actually be rather nice. The other weekend, I did a dark night dive in 5C water, 0C topside and perhaps a couple meters vis in the top layer. I was comfy warm all the time and had a pretty good time.

 

[RayfromTX]

Cold dark water doesn't mean cold dark dives. That is what good exposure gear and bright lights are for. The act of diving makes me happy. Pretty reefs are cool but being weightless in a three dimensional environment is pretty close to flying, perhaps better because hovering in air usually requires a big damned whirligig machine that is loud and disconnects us from the experience. Dive for diving's sake.

 

[RayfromTX]

I don't bother correcting people when they use the term sac to refer to rmv. In my experience, most of the people I come across call rmv sac and don't even know what rmv is. I try not to spend time correcting them when I'm sure I know what they mean. It is a bit like convincing them that din is better and metric is a better way to describe tank size and pressure. I usually just use the language that they understand. I can't say I never correct the terms people use but mostly it is a waste of time unless I suspect it is something they would like to be corrected on.

I am strange though. It bugs me to hear "hot water heater" when it is actually just a water heater. It bugs me to hear "under counter lighting" when it is just counter lighting.

 

[ljpm]

I am strange though. It bugs me to hear "hot water heater" when it is actually just a water heater.

Just ask them why they would like to heat hot water. If anything it is a COLD water heater.

 

[Joneill]

I don't bother correcting people when they use the term sac to refer to rmv. In my experience, most of the people I come across call rmv sac and don't even know what rmv is. I try not to spend time correcting them when I'm sure I know what they mean. It is a bit like convincing them that din is better and metric is a better way to describe tank size and pressure. I usually just use the language that they understand. I can't say I never correct the terms people use but mostly it is a waste of time unless I suspect it is something they would like to be corrected on.

I am strange though. It bugs me to hear "hot water heater" when it is actually just a water heater. It bugs me to hear "under counter lighting" when it is just counter lighting.

I've always heard it referred to as under cabinet lighting but I'm with you on the hot water heater - if the water is hot, why would one need to heat it?

 

[BRT]

I've always heard it referred to as under cabinet lighting but I'm with you on the hot water heater - if the water is hot, why would one need to heat it?

It is an HWT. Hot water tank.

 

[Joneill]

It is an HWT. Hot water tank.

Actually, it’s a water heater - can be tank or tankless

Water Heaters - Tankless Water Heaters and More at The Home Depot

The point was that many people butcher the language...

 

[Diving Dubai]

I'm similar to @RainPilot (with air consumption) As I'm better looking.

Generally I'm at 0.4 - 0.42 (11-12l/m) if I'm teaching I'm OW students then 0.52 (15l/m) I'm 53, 6'3 190lbs and a smoker. But I dive regularly as does my wife

She (similar age) is 0.28 - 0.33 - If only she used as little gas on the surface (nagged me less )

 

[Graeme Fraser]

I'm similar to @RainPilot (with air consumption) As I'm better looking.

Generally I'm at 0.4 - 0.42 (11-12l/m) if I'm teaching I'm OW students then 0.52 (15l/m) I'm 53, 6'3 190lbs and a smoker. But I dive regularly as does my wife

She (similar age) is 0.28 - 0.33 - If only she used as little gas on the surface (nagged me less )

Good point; my SAC is about 50% higher when I'm teaching.

 

[dberry]

I'm surprised more hasn't been made of the effect of the TYPE of dive on air consumption. Sure, you'll likely get your best RMV on a relaxing drift dive, but check out your consumption when you're fighting a current for the first half of the dive. Keeping track of RMV (using AI) on different dives is one of best things about my (electronic) logs. SBers with thousands of dives can probably substitute experience for detailed logs, but some of us are still learning from new experiences every so often. However, I'm getting much better at predicting my RMV immediately after a dive (based on the conditions).

There's also what a former instructor called the "revving the CO2 engine". In an AN/DP course I was baking in the sun and having a little trouble with my new twinset on the boat, then I missed the mooring line when jumping in and had to fin against a significant current to get to the line. Sure, I tried to relax once I was heading down the line and the excitement was over, but my RMW stayed at almost double for the entire dive (including deco stops). Once the stress and exertion got my "CO2 engine" revving, it took quite a while for my body to calm down. Just trying to zen-out wasn't enough to cool my jets.

FWIW, I've been doing a lot more cardio since that happened a few years ago, and I believe my pulse and respiration rate return to normal after exertion much faster these days.