[Gavin Yates]

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<font color='#000F22'>Right then guys -

I did a dive at the w/e with the usual 15l plus pony.

I use about 8 kilos of lead to keep me nice and cosy on stops with a tiny ammount of air in the wing.

Another dive I did with the twins and dropped down to 5 kilos cos the last time I had seven and was almost nailed to the bottom and had to get gas in the wing pretty sharpish.

So my thought's were that a 15 and pony should be no more than 4kg lighter than the twins and the difference in gas is about 5kg.

Needless to say I was still overweighted.

Anyway the question is what is the difference assuming 40 bar left in 15l and 200 in 3l

and

30 bar in twin 12s

This is all theoretical but I wondered if anyone had a way of working this out mathematically.

 

[Dominic]

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To work out the differences in cylinder weights: My bouyancy calculator
It's an excel database that works out any cylinder setup you may use. Including mixed gases  

 

[Gavin Yates]

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<font color='#000F22'>Saw that Dom - but I don't know what either the twins weigh  or the 15 plus pony.

I did have a chart that gave average weights for different cylinders but can't locate it.

 

[Dominic]

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The weight of your cylinder when empty is stamped on the shoulder: Look at the text until you find the number ending with KG

 

[Gavin Yates]

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<font color='#000F22'>ta mate. I'll use your xls thang tonight.

Anybody else got any ideas?

 

[Phil Ennis]

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<font color='#0000FF'>Hi Gav,
Sounds heavy to me. I am of a large build with a fair bit of buoyant stuff round the middle, (Fat), I dive a 12 + pony and go up to 14lbs this time of year so I can put a bit more air in the suit. With twin 12s I dont need a weight belt, is it possible that you were over with your 15+ pony but just got used to it.You are probably more conscious of the weighting flying the new rig.

Just a thought.

 

[Gavin Yates]

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<font color='#000F22'>Phil - my feeling is that I need about 2kg for the twins max. Maybe nothing.

I just wanna make sure I don't get light until I'm absolutely confident with their buoyancy characteristics.

I hate weight belts so losing it will be a godsend.

 

[ANDY 64]

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<font color='#0000FF'>You lot have got it easy ,,,, 14 on a wieght belt, jesus,,,,,,

i dive with a 7 lts ,,,,, 60 pound weight belt and lead inserts melt under the fin ribs, ( 8 pound on each )


Andy.

 

[JohnK]

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I use 6kg with twin 12 litres (232bar) in fresh water. If its cold I go to 8 so I can add some air to my DS. In sea water I will be using 8-10kg with the twinset - sounds a lot but I do have a bit of puppy fat to carry !!!

 

[Mark Chase]

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<font color='#000F22'>Totaly depends on the kit

I was  in an Otter membrain and thinsulate and I had twin 12s and 4kg and was lovley and ballenced.And could put a bit of air in the suit at 6m for warmth

I got a Weezle under suit and was strugling with the 6m stop on 50bar tanks but just about managed it with NO air in the suit. Not warm at all

I got a 5mm neopreen 03 and I have added another 4 kg to make 8 kg to keep be under on the 6m stop.

Still not totaly happy so spending whole day at Horsea tomorow trying to sort it out in salt water

Just when I thaught weight checks were a thing of the past I naff it up with a new dry suit

Mark Chase