How to reduce a monstrous SAC

[vladimir]

I was thinking they were called supermodels.

My fiancee will be thrilled to hear she's a supermodel! I'll tell my ex-wife too!

 

[dumpsterDiver]

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.

I've dove on charter boats from WPB on those types of dives hundreds of times. I do not recall EVER seeing anyone use double tanks for typical recreational (no deco) dives.

I don't think you need double tanks, a heart monitor or a $1,500 computer to do a drift dive in 80 feet.

 

[TSandM]

I don't think you have to have doubles, either. But I think an Al80 is too small -- if you retain reserves, you won't have enough bottom time to make it worth the cost of the boat. Dan dives HP100s, which seem idea for someone like me, but something even a bit bigger might be better for the OP. (Around here, we're in love with HP130s. You can do ANYTHING with those tanks!)

 

[dumpsterDiver]

I don't think you have to have doubles, either. But I think an Al80 is too small -- if you retain reserves, you won't have enough bottom time to make it worth the cost of the boat. Dan dives HP100s, which seem idea for someone like me, but something even a bit bigger might be better for the OP. (Around here, we're in love with HP130s. You can do ANYTHING with those tanks!)

I like my 149 cu-ft tank... Did a deco dive yesterday to 185, did about 11 minutes of deco and got on the boat with 1900 psi.

 

[halocline]

I don't think you have to have doubles, either. But I think an Al80 is too small -- if you retain reserves, you won't have enough bottom time to make it worth the cost of the boat. Dan dives HP100s, which seem idea for someone like me, but something even a bit bigger might be better for the OP. (Around here, we're in love with HP130s. You can do ANYTHING with those tanks!)

Sure, whatever, but if you remember, beaverdivers was specifically recommending doubles...independent doubles at that, and a computer with a heart monitor that costs $1500 for recreational diving, using a dive in Cancun as an example. I realize you're trying to be nice, ("I'm with you on this...") especially when a few of us are quite critical of his 'infomercial' postings, but please try to retain your usual clarity of thought.

To be absolutely clear, using double AL80s in recreational diving because you're unhappy with your bottom time with a single AL80 is a very bad idea. Fine, use a bigger single tank that does not A) require technical diving skills and B) double your out-of-water load, while significantly increasing your in-water mass and task loading. Do you agree with this statement?

There's another issue as well. While there's certainly no empirical data to my knowledge, I suspect that there is some crossover between recreational divers that are hoovering air above and beyond 'normal' consumption rates and divers that are possible candidates for increased risk of DCS, whether through poor profile management or poor cardio-vascular condition. Divers in both of those groups could be putting themselves at further risk by simply using larger tanks. I'm fairly confident that if the 'norm' for tanks in Cozumel goes to larger tanks, without the skill level of the divers increasing, eventually DCS incidence is going to increase. Hopefully I'll be wrong!

But of course beaverdivers' motives (as demonstrated by his posts) are not to 'help' divers, they are to push gear that he sells. I find it difficult to believe that a diver as experienced as you are (as well as a SB mod) does not immediately recognize this.

 

[bletso]

It's easy to see if its physiology or form and technique. Drop to the bottom and don't go any where. If your RMV is still high and it's not anxiety, then it's your physiology. Buy a rebreather and forget it.

Over the years I have noted, as has been pointed out in this thread, that most divers haven't a good handle on buoyancy and TRIM. I dive big heavy gear, but I am never in a hurry. That is the second thing most divers fail at. You will see more and enjoy more by being a slug, kind of the difference between cycling and driving a car.

Dangles will effect effort if you are in a hurry, but have little effect whilst slug diving. Remember diving is a visual sport, not a race to get somewhere first.

Dale
ahhome

 

[MXGratefulDiver]

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...

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

I'm thinking beaverdivers is trolling here ... pretty much any properly functioning scuba regulator is going to give you adequate WOB to deal with current ... at least, any current that a typical recreational diver is going to want to deal with. If your reg isn't delivering enough air, you've either got a reg that needs service, has the adjustment knob turned down to minimum delivery, or you're in current so strong that you should be thinking to end the dive anyway.

FWIW - I've been getting rid of all my MK25/S600's ... they're nice regs, but no better performers than HOGs, which I can purchase for a lot less money and service myself. I've dived my HOG regs in all kinds of conditions ... deep, strong current, and in caves ... without any issues. I could easily do the same with my Apeks and Dive Rite regs without any issues at all. One doesn't need to spend a lot of money on high-end equipment for simple recreational diving ... pretty much any reg manufactured in the last 15 years will provide more than adequate performance for diving at recreational depths and in recreational conditions ...

... Bob (Grateful Diver)

 

[beaverdivers]

I like my 149 cu-ft tank... Did a deco dive yesterday to 185, did about 11 minutes of deco and got on the boat with 1900 psi.

Why have all your gas in a single tank?

Do you REALLY want to post that you did a TEK dive w/o redundancy?

 

[halocline]

It's easy to see if its physiology or form and technique. Drop to the bottom and don't go any where. If your RMV is still high and it's not anxiety, then it's your physiology. Buy a rebreather and forget it.

Oh sure, doubles, $1500 computer, rebreather, all perfect ways for a recreational diver to deal with air consumption issues. What the hell, why not just buy a submarine? How about hiring a surface-supply team to follow you around on reef dives?

This is a fun place

 

[RTee]

Why have all your gas in a single tank?

Do you REALLY want to post that you did a TEK dive w/o redundancy?

For some ...simplicity, safety and ease of manoeuvring.

When my GF sees me hauling my HP 120 double set around she often wonders where do I derive my fun factor? More so if in addition to such config, I sling a 80 cft on one side and a 40 cft on the other, and then she wonders what I am really breathing to enjoy such diving???

Do I always dive in that config...my answer is no. I can think of many situations where my preference is for a single larger tank than my set of double.

To the OP, strive to maximize your trim and buoyancy as suggested by previous posters, attempt de develop an efficient breathing pattern without skipped breathing and be as zen as you can be while diving. The next step will be to consider a greater capacity tank system(s) if you want to extend your bottom time within NDL for any given depth. 80cft may not be the best size for you. Heck, my GF has a SAC less than .4 and she just swapped her two AL 80 cft for two used HP 100 cft.

1500.00....I wonder how much two HP120 or 133 and number of refills you will get for that amount. This will probably give you a bigger bang for the buck than staring at a screen that will repeatedly remind you that when it comes to air consumption, you are not the frugal type.

Beaver, who says he was not carrying any other form of redundancy?