How much lead?

[yazzyfooty]

Last time I dived my twin 12 Fabers (last year) I was using bowstone weight harness and I have since gone onto a shot weight belt. Yesterday I dusted the twins down and took them for a play in Capernwray.

I didnt use my normal weight belt as I would have been too heavy (8kgs) I used 2 x 3 kgs in a pouch weight belt to check the weight (the idea is to get another shot weight belt for when diving with twins). At 1.6 metres and 130 bar in both tanks I was struggling to stay down, am I asking too much? How much more shot do i need?

I am rubbish at physics.

[Capt Morgan]

If 8kg in the harness was OK then I would guess 8kg
in the shot belt would do the same thing.
I dive twin L Fabers in a compressed neoprene
suit with a SS backplate and use 12lb (5.5kg)

[Turtle Dude]

As much as you need. It is your body/equipment mass.

Generally a steel 12 will be posatively buoyant when empty; so two of them will mean you are more posatively buoyant! Thats one of the things about twins...

Compared to my 300bar twin-7s (which are negatively buoyant when empty), my 232 steel twin-12 is 5kg more posative - i.e. I have to put on 5kg of lead when I swap from the 7s to the 12s.

You can add weight on the backplate/cylinders - tail weights, V-weights etc. You can add something like 4-6kg easy that way and not burden your belt (just makes em even fecking heavier to shift out the boot of the car!).

http://www.divingniknaks.com/scuba_P..._V_weights.php

[Moz]

Generally a steel 12 will be posatively buoyant when empty; so two of them will mean you are more posatively buoyant!

Really?, I'll chuck a few sets over the side of the boat this weekend then just to check

Not mine of course.

[yazzyfooty]

If 8kg in the harness was OK then I would guess 8kg
in the shot belt would do the same thing.
I dive twin L Fabers in a compressed neoprene
suit with a SS backplate and use 12lb (5.5kg)

Sorry I didnt make it clear. I use 8kg of shot for when diving single 15.

As much as you need. It is your body/equipment mass.

Generally a steel 12 will be posatively buoyant when empty; so two of them will mean you are more posatively buoyant! Thats one of the things about twins...

Compared to my 300bar twin-7s (which are negatively buoyant when empty), my 232 steel twin-12 is 5kg more posative - i.e. I have to put on 5kg of lead when I swap from the 7s to the 12s.

You can add weight on the backplate/cylinders - tail weights, V-weights etc. You can add something like 4-6kg easy that way and not burden your belt (just makes em even fecking heavier to shift out the boot of the car!).

P weights and V weights, Tailweights at divingniknaks

I struggle lifting the twins in and out the boot of my SEAT Leon so I dont really want to add extra weight. Will probably do my next dive with 7 kgs in the belt to see if i can hold my stop at 1.6 metres next time.

[witchieblackcat]

Yaz,

I have a set of Faber twin 12s that I used at the weekend. I had a 6kg V weight and had no problem holding a stop with 100bar in them. Have you got all of the air out of your suit and/or wing?

Having said that, I agree with the others. 8kg on a weight belt == 8kg in a harness == 8kg as V weights == 8kg stashed around the body in various pockets == 8kg swallowed as a large pill *


* Please don't try this at home. It's not big or clever.

[bubbleless]

If you go playing with your twinset again, take a little too much then at the end of the dive you can adjust your weight to get that superbness state of buoyancy.

Try taking some ankle weights and clip them onto your harness, then you can alter it by 1 kg.

or if you can get at a weight pouch r in a pocket or somewhere like that.

You will know its not an exact science you just need enough, not too much.

Have fun

[Morag]

I used to use 8kg with a single 15, and now use 2kg in twin 12's.

You need what weight you need, but 8kg seems an awful lot if you were having difficulty staying down.

This may seem obvious, but, were you on your way up, and therefore having gas expanding that was having difficulty escaping? So many people automatically go for 'I can't hold a stop therefore I am underweighted' without going the other way, and seeing how little weight they need to sink.

[nigelH]

130 bar in 24L is 3.9Kgs.

So that needs to go on the belt to just to get back to 'struggling to stay down' on empty.

2Kgs is the difference between possible and comfortable for me so I'd say add 6Kgs and expect to feel a bit light.
With that you can dive and tweak for comfort later.

[yazzyfooty]

I used to use 8kg with a single 15, and now use 2kg in twin 12's.

You need what weight you need, but 8kg seems an awful lot if you were having difficulty staying down.

This may seem obvious, but, were you on your way up, and therefore having gas expanding that was having difficulty escaping? So many people automatically go for 'I can't hold a stop therefore I am underweighted' without going the other way, and seeing how little weight they need to sink.

I had 6kgs on with the twin 12's and wouldnt normally be spending so much time at 1.6 metres playing with the fish as once my computer had cleared me of stops then I normally ascend the last 6 metres. Yesterday I was experimenting with buoyancy and I had no air in suit or wing.

130 bar in 24L is 3.9Kgs.

So that needs to go on the belt to just to get back to 'struggling to stay down' on empty.

2Kgs is the difference between possible and comfortable for me so I'd say add 6Kgs and expect to feel a bit light.
With that you can dive and tweak for comfort later.

So my 6kgs was roughly right?