Twin set up - Weights

[Squishey]

Hi Guys,

I am sure this has been asked a million times before. But anyhows! recently I have been very interested in changing from the convential single cylinder bcd and pony to a twin set up on a wing.

I am a DM so would still make use of my single for pool use etc however after doing my tek 40 course with twins and a side slung I am even more interested in trying to put together a set. Currently as I am sure it is for everyone, money is short, however I feel its better to spend more and end up with something that will last and ultimately look after you better.

My question is, what is the weight difference between steel twin 12's and steel twin 10's when full of air (220 bar ish) and the also the difference when empty.
Me personally I am young and have done a fair amount of diving So my air consumption is good, whereas my usual buddies is errr . . not so good. So in terms of that I could easily dive with 10's whilst her dived on twin 12's or even 15's if he wanted. Thus meaning carry around less of the damn weight! However there is always the thought of, for the little extra it costs, and yes the weight, is it worth having the full 24 litre capacity for the future incase I do get the opportunity to stay down that bit longer because my buddy at the time is also good on his/her air consumption.

I am sure this is asked a million times but anyone willing to let me know their view on it would be much appreciated. My staff instructor reckons twin 10's . . but that may just be because he doesn't like carrying around the extra wait and also has the advantage of owning plenty of twin 12's that he could sling on if he felt like it.
Me personally, I am swaying towards the twin 12's as the money difference really is not that much .. and as said before . . i prefer to buy something that will last.

Thanks guys for your time . .
Hope to hear from you

Kind Regards

 

[DevonDiver]

Have a look at the lists here: Scuba Diving Cylinder Buoyancy Details

They contain details of buoyancy characteristics for different sizes/brands of cylinders.

 

[TSandM]

Really, the key is to work out gas requirements and reserves for the dives you intend to do with the tanks. Figure out what will give you what you need for what you will PROBABLY do, and buy those.

Buying bigger simply because you can carry them is not always the best answer. My dive buddy carted around double 130's for several years, because he COULD, but then bought a set of 72's for his son, and when he played with those, realized how much nicer it was not to carry a refrigerator on his back when he didn't need it.

 

[ajduplessis]

Weight is an important consideration as you will need to carry them around, but I believe you will arrive at a choice once you understand your diving requirements. If you plan on doing longer/deeper deco dives the 10's might not be the optimal choice. My instructor uses 12 and I have 15's (planning on doing a 100m dive some day).

Double 10's at 220 will give you 4400 litre breathing mixture. With a breathing rate of 12lpm (quite low) you will have enough air (rule 1/3) for around 24min (BT) dive at 40 meters (I assume this is the limit for tek40??). If this is well within your future requirements, 10's will do fine. If not, you have to start looking at bigger cylinders.

What did you use during your tek40 class??? Are you planning on going deeper???