Weight problem

[David]

Originally Posted by IainC

Narked at Zero
It is surpising what lead you may need to sink, Iain C

remember you cylinders may be haver or lighter than your mates so it becomes harder to compare your weighting to the next diver.

Ive only started diving twins last year it took about ten days diving to get comfortable. Now I am messing with where I want the weight to be.

Mal advice seemed like a good plan :-)

I purged my down from 30 to zero bar on my gauge and could still hold a 1 meter stop. on filling them they had 9 bar in them so my gauge is a little out :-)


DAvid

[Woz]

Right here is the scores on the doors for me in the sea:

Single 12 and Buddy Commando, 100g undersuit: 28 lb
Single 12 and Buddy Commando, 300g undersuit: 36 lb (eek)
Twinset and 100g undersuit: 16 lb
Twinset and 300g undersuit: 24 lb

I find I trim perfectly out in a twinset with all my lead round my waist. With a dumpy 12 I need 8lb cam banded at the top of the cylinder, with a tall 12 lead on my waist is just fine. Twin 7's are slightly neck heavy, twin Faber 12.5 (bloody heavy) trim perfectly.

[Finless]

Originally Posted by Scubee

Minor thread hijack and stupid question alert.....

I know what a V weight is, but what is a P weight?

A Prince Albert using lead!

[Finless]

Originally Posted by NarkedAtZero

I'm trying to get my weighting sorted out now I've started diving twins .................................................. .. (BTW When I say i carry a lot of weight, I've now got a P and a V weight, and still need to carry extra in weight pockets. With Heiser heavy 12's. And I wonder why no one helps me back onto the RIB.)

This is my first post apart from my introduction (hello!) - thanks in advance.

Hi, the common consensus/average for someone of my build diving twin 12s is 4kgs of lead. I use 8 + ankle weights.

I'm afraid the only way you can know for sure is to get in some shallow sea water (with an on shore/harbour wall assistant) with nearly empty cylinders (30 bar in each) and all your normal dive equipment and make sure you can comfortably hold your 3 mtr safety stop.

Like you I am concerned about diving with too much weight ............ not that I'm not comfortable as I am but more that I like to be 'doing it properly'. I went to Eastbourne marina, dumped all my gas after a quick swim round and decided I was happy just as I was. I evidently like a bit more gas in my dry suit than most people ................ that's 'cause they are perverts and/or masochists because they like the genital squeeze!

Not a bad title for a song? "I've got the genital squeeze!"?

[NarkedAtZero]

Thank you all for your responses, especially Mal for your detailed reply.

Originally Posted by Mal Bridgeman

...When you said you felt uncomfortable on your stop you did not say how much gas you still had in your wing or whether you were finning upwards or downwards during the stop...

35 bar in the twins, no air in the wing that I could find, I was wriggling around all over place to make sure there wasn't any trapped anywhere, and was experiencing Finless' copyrighted Genital Squeeze (would that be a Michael Jackson song, do you think?) off the drysuit. I ended up combining sipping tiny amounts of air and finning downwards when it all got too much. It wasn't a deco dive, thankfully...

Originally Posted by Mal Bridgeman

...changes should be made in small steps...
...I think that changing your overall weight in chunks of 2kg is going to make it hard for you to get comfortable with it...

The overall problem I've been having is not yet finding any kind of constant by which to gauge what works for me, and that's making me change my weighting in a really crude way:

I've done weight test days at Horsea (brackish water, usually -1kg for me), and under a pier with exactly the same kit configuration and came to the conclusion that I was a tad underweight at 30 bar in salt water with 8kg, so when I first went out to sea I got hold of a 4.5kg V-weight and put 6kg in my wing weight pouches, total 10.5kg, just to be sure. As I was kitting up I impetuously grabbed my ankle weights (just to be double sure - nerves I guess) which added another 1.5kg to me overall. Total 12kg. That should be stupidly overweight, and yet I couldn't hold 3m at 35 bar on the second dive. So now I'm 8kg P and V weights, and 6 kg in my pouches: total 14kg with heavy Heiser 12s, or in other words 1kg more than I am with a 15 ltr steel and pony.

Of course it's very early days with the twins and I'll get there eventually, especially as I get more relaxed. I'm just very confused by all that weight, I thought I'd be shedding loads going to twins, and not just of money. I think I'm going to follow Mal's procedure, a bit more of weight testing at Horsea required. Maybe cutting an arm off, or if that failed (and only as a last resort obviously) leaving my lucky bouncy castle on the surface would help.

Thanks again everyone,

Nick

[The Duck]

Originally Posted by NarkedAtZero

I'm just very confused by all that weight, I thought I'd be shedding loads going to twins, Nick

Don't worry - you need what you need.

Just because the twin set weighs more it does not automatically mean that you need less lead - reason being displacement.

As an example (ignore the weights themselves it's the relation between the weights that I'm trying to show), all for sea water with the same drysuit and undersuit:
single 12/232 - 7kg
single 12/300 - 5kg
twin 12/232 - 5kg
twin 16/232 - 5kg

As can be seen although the weight of the rig increases the weight needed on the belt does not change much.

Hope this helps.

[NarkedAtZero]

Originally Posted by The Duck

Just because the twin set weighs more it does not automatically mean that you need less lead - reason being displacement.

Hope this helps.

Aha!! That's the fella! It really does help - a good point well put.