In water attitude

[Ed Howarth]

Having dived on twin 10's for only a short time, I am struggling with getting my attitude right. If the cylinders are high enough to reach to do shut downs, I am forced into a head down attitude - very disconcerting. If I drop the cylinders low enough so that I am horizontal I can't reach. I am fairly supple and have read up all about loose suit; taking the arm directly backwards etc. I think it all comes down to the fact that the centre of gravity of the 10's is just too far up (i.e. forward when horizontal), in comparison to 12's which are longer.

I have 6 kg on my weight belt and a s/s backplate. I have worked out that putting more weight on the belt or putting a v weight on just isn't going to lower the C of G that much. I am planning to try ankle weights, i.e. a small weight down there should result in a large moment, but has anyone else come up with another solution?

Ed

[TerryH]

Having dived on twin 10's for only a short time, I am struggling with getting my attitude right. If the cylinders are high enough to reach to do shut downs, I am forced into a head down attitude - very disconcerting. If I drop the cylinders low enough so that I am horizontal I can't reach. I am fairly supple and have read up all about loose suit; taking the arm directly backwards etc. I think it all comes down to the fact that the centre of gravity of the 10's is just too far up (i.e. forward when horizontal), in comparison to 12's which are longer.

I have 6 kg on my weight belt and a s/s backplate. I have worked out that putting more weight on the belt or putting a v weight on just isn't going to lower the C of G that much. I am planning to try ankle weights, i.e. a small weight down there should result in a large moment, but has anyone else come up with another solution?

Ed

Yes easy. Invert them.

Before we get all the crys of noooooooooooo!!!!!!!
Think about it.

You want to be comfy, but want to be able to shutdown.
a) Inverting would allow any position, so balance would be right.
b) You can easily reach to shutdown without any problems.

Next time you are in the pool, just bolt them on upside down.
Forget hoses, just go on a mates occie. See if the balance is
better before you start buying longer ones.

TerryH

[Darren27]

What he said!

The amount of people I see wondering around Stoney with their twins the wrong way up( valves up :p ) always makes me laugh. The correct way is valves down.;)

[Steve Pearson]

Hi Ed

If Twinverts doesn't solve it for you, try:-

Twin 12's
Tail weights instead of your weight belt

Try doing shutdowns by releasing your waist strap/crotch strap and inverting yourself slightly so the tanks slide towards your shoulders into a position where you can reach them.
Also get a slob knob for the manifold (Assuming you're manifolded)

Don't put lots of additional weights in addition to what you need, that will have a negative effect in other areas, ie buoyancy, gas consumption,

Don't get too hung up on it if you can't sort it properly, the main thing is get your attitude right for you, so that you're diving comfortably and at ease. Use a slob knob, that way even if you can't reach you isolate the freeflowing cylinder, can switch to your secondary DV when required (keep breathing from the freeflowing one until either your buddy turns off the valve for you, or you use up all the gas) then switch to your secondary. Remember once this happens you should be aborting the dive and returning to the surface ensuring you complete any required stops.

Hope this helps

Good luck

Steve

[Woz]

You might want to look at flogging the Fabers (too short IMHO) and getting a pair of Heisers or Euro Cylinders (sold in the UK by Beaver) which are longer.

You might think about 12's. But they are bloody heavy. Or my ideal setup- twin 7's- which strangely are longer than the 10's. Lovely to dive with, though.

Not keen on inverting- I have seen too many bent valve guards after being bounced plus you'll need custom hoses. And everyone will think you are a fireman. Plus if you take the boots off Stoney won't fill your cylinders.

[Janos]

I used to invert (before I got the rebreather) and it's brilliant. Laughably easy to shut down.

However if you don't want to invert then try a p-weight - this is a bit like a v-weight, but it's got a length of SS on it so you put it on your bottom bolt and it goes towards the bottom of the tanks.

Janos

[Steve Summers]

Invert them or if you feel the need to conform to the wrong way up ;) get them to the point where they tip you forward then cam band a weight to the bottom of the cylinders that should sort it.

Good luck

Safe diving,
Steve

[Ed Howarth]

Thanks all. Excellent food for thought there.

I use a slob knob, so can get myself half sorted.

I realise that the proper solution is to go for 12's, but as I'm under 11 stone, that's just not possible:o

I'm going to have a go at inverting, I think. If nothing else, it gives me something to prat around at. If it works I can sell the slob knob to offset the cost of the hoses!

Many thanks.

Ed

[Adrian Kelland]

I realise that the proper solution is to go for 12's, but as I'm under 11 stone, that's just not possible:o
Why Ed?

Adrian

[tony J]

I am planning to try ankle weights, i.e. a small weight down there should result in a large moment, but has anyone else come up with another solution?

Ed

For what it is worth, I'm 6ft4 11 stone and dive twin 10's with 2-4kg on my waist. The only way of having a nice in water attitude for me is to use ankle weights (I have undense quattro planer fins, which I will not replace until they wear out....)

I did not have the problem when I had twin 10's on a BC with more weight on my waist.

As far as using 12's: very silly idea unless you need the gas (IMO), the extra weight of carrying the weight on land is annoying (and in fresh water I am then overweighted !) and like using a sledge hammer to crack a nut.

Tony

[Adrian Kelland]

For what it is worth, I'm 6ft4 11 stone and dive twin 10's with 2-4kg on my waist. The only way of having a nice in water attitude for me is to use ankle weights (I have undense quattro planer fins, which I will not replace until they wear out....)

I did not have the problem when I had twin 10's on a BC with more weight on my waist.

As far as using 12's: very silly idea unless you need the gas (IMO), the extra weight of carrying the weight on land is annoying (and in fresh water I am then overweighted !) and like using a sledge hammer to crack a nut.

Tony
Depends on the size of the nut.

Try cracking the nut of a 16" thread without one. :D :D

Adrian

[Ed Howarth]

Why Ed?

Adrian

Because, my legs would telescope up inside my body:D

I reckon I do well to get around on land with the 10's, I'm only a weakling!

Ed

[Adrian Kelland]

Because, my legs would telescope up inside my body:D

I reckon I do well to get around on land with the 10's, I'm only a weakling!

Ed
Only if you jump Ed. :D

I have heavy 12s - Heisers, but Fabers are lighter. OTOH you might be making up for it in lead.

Adrian
(another weakling)

[Beanie]

Because, my legs would telescope up inside my body:D

I reckon I do well to get around on land with the 10's, I'm only a weakling!

Ed

Don't worry about that I'm pretty much the same size possibly smaller

I did for a time dive twin 12s and twin 10 stages, the kit weighed nearly twice as much as me ;)

[Nigel Hewitt]

I reckon I do well to get around on land with the 10's, I'm only a weakling!That's really bad.
It always annoys me when kiddies half my age, with a full set of working joints and who have never seen the inside of a Cardiac ward tell me my twin 10/300s are too heavy.

I start developing a very bad "In water attitude" at that point but it's nothing to do with a horizontal body with heels high to frog kick - It's more about roping them to a wreck and turning their air off.

[Paul Oliver]

Well i quite like my twin 12's, and on land i wheel them around on a little trolly so the weight is not really an issue.

[Garry Whyke]

Hi Ed,

One thing to bear in mind is that the proper solution is whatever suits you and the type of diving that you are doing. Twin 12's have a place but it may / may not be what suits you.

I have moved from 10ltr independants to manifolded 12's (when I moved to Trimix) to rebreather. Even with the manifolded 12's shut downs were not easy. The big question is can you shut down in an emergency when the stress factors are high??

If diving manifolded twins, the ability to carry out shut downs (second naure is critical). If I was to go back to twins, I would seriously consider inverting them, increasing the simplicity of shut downs. This will also give more flexibility to lower them and stop forward rotation. If you go down this route get a durable cover/stand as it needs to be able to take a bash. Some of the valve protectors on the market are that (valve protectors) - others have been designed specifically for inverting them (not cheap though).

Personally I am also a fan of V weights, as in water attitude with a weight running up the spine tends to work well for me. Only problem being the weight of the bolted twin set out of water. Or is that just me being a weekling!

Good luck with whatever you decide upon.

Cheers

.............. Garry

[Vic]

Even with the manifolded 12's shut downs were not easy.

Aha! Another opportunity to trot out my Shutdowm Top Tip :-)

Shutdown problems are almost always down to technique; I would strongly advise people never to use kit to work around a technique problem. So here's how to make shutdowns that bit easier :-

Look at how you're getting your hand to the knobs. Your palm is probably facing forward. This is why you have problems - all the reach is coming from forcing your shoulder joint into positions it really wasn't deisgned to go into. That's difficult.

Here's the easy method. Hold your arm out in front of you. Rotate your hand so that your palm is facing upwards. Now fold your arm back past your head, without rotating your hand. You've just reached half-way down your back, haven't you? The reach is now coming from the length of your forearm, not from the flexibility of your shoulder. This is good news for those of us with inflexible shoulders :-)

You might still want to invert - but this should be because you want to, not because you think you can't dive with the valves upmost.

HTH

Vic.

[Keith Lawrence]

Here's the easy method. Hold your arm out in front of you. Rotate your hand so that your palm is facing upwards. Now fold your arm back past your head, without rotating your hand. You've just reached half-way down your back, haven't you? Errrr... NO :rolleyes: Tried it both ways, tried every technique/excercise going over the years, my hand ends up at about shoulder blade hieght no matter what I do. Which is why my twins are inverted :D

Keith L

[Janos]

You might still want to invert - but this should be because you want to, not because you think you can't dive with the valves upmost.

Good point. I can reach my valves with them valve up. But I choose to invert as it's just so much easier. Inverting should be people's first choice - it's not just for those who can't reach their valves.

Janos