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OK, here we go...

I'm just about to complete Sports Diver, and so we start to look at being more self sufficient and providing our own redundancy for when the brown stuff hits the fan...

Most of my diving is from a rib, off Anglesey, and up to now has been sub-20m stuff. The more challenging dives the club organises (which always get blown out) are still only likely to be around 30m.

Practically everyone up to now has got themselves a pony cylinder - which as has been discussed before, is probably the cheapest way to get yourself set up.

So, given my diving, do I rush out and buy a pony, or, consider a twin-set? My first thought was that a twinset would be too big and heavy and awkward, but after lugging 15L+pony setups out the water I can't see how they can be any worse!

My second consideration is what do I need to learn? As only one other person uses a twinset at the club, where do I find information on shutdown procedures and other considerations?

I want my rig to be small, compact, and neat. My air consumption is good, do I consider twin 7's? Or should I look further to the future a go for twin-10's? As I said above, most diving will be with sub-30m with limited or no deco.

What would you suggest as to types of wing/harnesses/regulators? Where do I learn about configuration of equipment (apart from Dominics web-site!?).

I know everyone will have a different opinion - and I have read the other posts regarding redundancy too - but you guys are still the best source of info, so i'd appreciate your comments...!!

Thanks.
 

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When it comes to weights, Justin, these facts & figures are from the Faber website:

Size Lightest Heaviest
3           3.4         3.8
7           7.6         9.1
10          10.9       12.4
12          12.8       15.2
15          16.4       18.6

So the lightest twin 7s will be 15.2kg, the heaviest 18.2kg
The lightest 15+3 will weigh 20kg, the heaviest 22.4kg

When it comes to bouyancy, the differences are:
15+3 light = 1kg positive
2x7 light = 1.2 postitive

15+3 heavy = 0.9kg negative
2x7 heavy = 1.38 negative

So your lead requirements will be pretty much the same, but the cylinders will be 4-5kg heavier with the pony route.

In terms of size, I've checked my own twin 7's against a 15+pony, and found them to be the same width and less height - so twins are unquestionably the smaller setup.

[b said:
Quote[/b] ] My first thought was that a twinset would be too big and heavy and awkward, but after lugging 15L+pony setups out the water I can't see how they can be any worse!
That was my first thought too, and so I bought a pony.
After discovering it was a rig I couldn't actually lift without a buddy to help me, I was delighted to discover that my twin 7s can be swung up with ease, even with all my lead bolted to it as well!

I hear a lot of negative things said about twinned 10s - generally down to them being too short for comfort. Have never tried them myself tho.

If twin 7s do have a downside, it's that you're unlikely to get two dives out of them unless depth is on your side. This doesn't usually cause me any problems, but it may be a consideration for you..

[b said:
Quote[/b] ]What would you suggest as to types of wing/harnesses/regulators?
Well, I use a Buddy wing because it was good quality and cheaply priced. Wings like the DR Classic are popular, but probably too big for a small twinset.
I have a 1-piece harness, wouldn't even consider breaking it, as I've become very fond of the feeling of security you get from an unbreakable harness - I had a clip fail on me once, it's reassuring to know it won't happen again.
As for regs - whatever you use at the moment should be fine, just add another first stage. I got myself an Apeks DS4 when I went over to twins.

[b said:
Quote[/b] ]Where do I learn about configuration of equipment (apart from Dominics web-site!?).
Where else do you need?
 

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<font color='#0000FF'>Hi

A twinset is nice to have although expensive if you plan 2 dives off the club rib (you'd need two sets of 7,s or twin 12's). There is a lot of info on this site regarding setup and valve drills etc. In my opinion a good attentive BUDDY with same kit, and properly practiced at out of air drills is far better than any individual piece of kit!

Find more info on equipment on http://www.dir-uk.org/equipment.htm . There is a good word document which goes through everything from mask to fins, twinsets, ponys, regs the lot.

Kindest Regards

WL
 

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Ignoring the DIR argument WL, (I did go into your temple in Portland at the w/e - nice kit ******* expensive though), I do not agree that you need two sets necessarily. It depends on who you are diving with and the type of dives you do.
I use independant 12's and often dive with people on 12+3 or 2*7 configs. I get balance, redundancy, avoid the hassle of midday fills and the odd gripe from the skipper about weight.
Works well enough.
 

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<font color='#0000FF'>Hi

I meant that he might need two sets of 7's if he chose 7's because of the weight. Twin 12's are excellent, you only need one set, but a lot heavier. If doing UK dives from a rib in the 20-30 mtr range a single set of 7's won't leave enough reserve to complete the second dive safely in my opinion, not even 300 bar ones.

Kindest Regards

WL
 

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At this point would it not be fair to say then a 12L & pony would be a better bet as you could also have a second (spare)12L for the second dive (or even hire one for the day) whilst still using the original pony as backup. A second 12 would be a lot cheaper than a second twin set.

Matt
 

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Hell, if you've already got a single, or are planning on hiring one, give Kent Diving a call and order an air decanting whip - £55, IIRC. I might well be flogging mine soon, for that matter..

Then take your twin 7s and a single with you, and stick some air back into the twins to give yourself enough for your nice, shallow, second dive.
 

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[b said:
Quote[/b] (MATTBIN @ July 03 2003,14:37)]At this point would it not be fair to say then a 12L & pony would be a better bet as you could also have a second (spare)12L for the second dive (or even hire one for the day) whilst still using the original pony as backup. A second 12 would be a lot cheaper than a second twin set.

Matt
But if you're going to carry around two single twelves and a pony, you might as well just go for twin twelves in the first place.

If you really, really don't want to go for a twinset but still want redundancy then I reccomend getting a 7L Ali and rigging it like a stage. That way you're pretty sure never to outgrow it.
 

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Except on the dive you would be using 12l & Pony which would also be OK on a bimble, whereas twin 12's might be a bit of overkill? We are also looking at what kit to buy after originally purchasing a 12l  that will satisfy the next stage (and hopefully beyond), to me it looks as though twin 7's would soon be outgrown whereas the pony could be used as stage gas later on or as a simple pony with a single 12 for those shallow dives. I might be wrong anyone bought twin 7's and stayed with them for a long time or moved onto 10/12 twins?

Matt
 

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I bought my twin 7s from new and have just got them back from their first test.. mind you, with moving home and two car accidents, I haven't done as much diving as I'd have liked with them  
 

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The two dives off the rib is a consideration - i like the sound of compact twin7's but would probably struggle to get two dives - though I do need to do a bit more checking on my air usage to be honest. Most at the club currently only have one cylinder, so a trip to the dive shop at Treaddur for a fill is commonplace (which p's me off as it takes forever!!)

I currently have two 12L cylinders - but there's no way i could manage twin 12's, and i don't think i'd get them on the rib (certainly wouldn't be popular!!).

Cheers for the replies - gives me more to think about and look into!!
 

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[b said:
Quote[/b] (Justin Owen @ July 03 2003,15:18)]I currently have two 12L cylinders - but there's no way i could manage twin 12's, and i don't think i'd get them on the rib (certainly wouldn't be popular!!).

Cheers for the replies - gives me more to think about and look into!!
<font color='#000080'>You might be surprised !

I use twin 10's they each weigh 11.8kg, strapped to a 2.5kg backplate with a 4kg P weight bolted on the backplate.

They are actually pretty comfortable once I am stood up and I am  not a big build by any standard.  

Daz
 

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<font color='#000080'>Well, once again I wade in with the "get some 300bar twin 7s" bit. I like the set. Works for me, and I've not outgrown it. That said, I have access to as many tanks as I like, and have borrowed 232 12s from the club for deeper stuff and I'll be using 232 10s this week as I'm on a boat that I'm not sure will manage 300bar.

If you've already got 2 12l tanks, I'd say buy yourself a pony, which will tide you over nicely until your diving gets to the point where you'll want the 12s. I would say the same old about sidemonting the pony if possible, and I prefer ally ponies because they won't throw you off balance, and are practically the same size and weight etc. out of the water.

It will also be a lot more popular on a packed boat than twin 12s.

But, all this said, think about the 7s. Mine have seen me through some pretty serious dives, and the only upgrade I can see is to twin 12s, which would be a very big set, and practically impossible on our club trips, not to mention unnecessary for most of the diving on such trips. I find the 300bar lasts a whole long time for me, and I can comfortably get 2 dives out of mine. They gave me an hour and twenty at 20m the other day, which admittedly was stoney. I had to make a point to a mate about how useful the extra gas in a twinset was, so he strapped on twin 8s, and we went to try and see everything in Stoney at 20m. We did, and our gas consumption isn't record-breaking by anyone's standards.

Maybe this helps,

Digs.
 

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I've got to stop reading this sort of stuff.  I now want a pair of twin 7's myself! (I dive twin 12's normally).  

Dom, brilliant post.  For "breaking-your-back-getting-them-out-of-the-boot"-worthyness, you might want to add the all up weight with gas.  For example, my 12l faber weighs 18.6Kg at 232.

I just fancy a pair of 7's for shore dives...  And a whip...

By the way, any thoughts on 232 7's v's 300 7's?
 

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[b said:
Quote[/b] (Mdemon @ July 03 2003,22:59)]By the way, any thoughts on 232 7's v's 300 7's?
<font color='#736AFF'>I started a similar thread on this about a week ago and I am still mulling over all the info provided.
I have decided on the twin 7s but the 300 vs 232 debate is still raging in my mind. Some people have said it hard to get 300 bar fills? Anyone got the definiotive answer to this one?

Jules
 

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[b said:
Quote[/b] (Julia C @ July 04 2003,00:21)]
[b said:
Quote[/b] (Mdemon @ July 03 2003,22:59)]By the way, any thoughts on 232 7's v's 300 7's?
I started a similar thread on this about a week ago and I am still mulling over all the info provided.
I have decided on the twin 7s but the 300 vs 232 debate is still raging in my mind. Some people have said it hard to get 300 bar fills? Anyone got the definiotive answer to this one?

Jules
I think it basically depends where you are. Lots of places on the south coast do fills to 300bar and I suspect that a lot of dive shops in other locations do as well. AIUI the availability of 300bar is definatly improving all the time.

Having said that I wouldn't go for 300 personally, I'd stick with 232  
 

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I dive twin 12's as do most of the guys at my club. Most of the girls use twin 10's.
Whats all this about not being popular on the boat? Ive dove twin 15's off a rib and no one seemed to mind.
Two people can drag twins over the tube of a rib quite easily.
You can probably do it by yourself, i know i can.
Who cares if your not popular on the boat? At least your alive and breathing.
Any deco diving or deep no stop diving needs adaquate redundancy to get you back to the boat, with stops, from the deepest point of your dive. If twin 10's or 12's are necesary then use em.
And as mentioned in other posts, depending on the first dive, you'll probably have enough gas left over for a shallow(er) bimble for the second dive.

Just my thoughts, Stu.
 

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As you already have two 12s, a pony would seem to be the logical answer in your case. You can get a pony and reg for as little as £150 and you will be able to use both if you decide to upgrade later on. For the kind of diving you are doing just now, a 12 litre single and pony will give you plenty of redundancy. Don't worry about the balance. Just wear 1 kilo more lead on the left side of your belt (assuming you have the pony on the right side). People who say they have problems with balance with this set-up are doing something wrong (I suspect they rig the pony too far from their back). Read the advice on Dom's site re rigging a pony.
 

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John
I have my pony attached through s/s clamps directly next to my 12L tank and do not offset the weight on the weight belt but do not notice any out of balance forces unless I deliberately roll one way or the other. In normal trim I dont even notice its there so I agree that its either mounted too far away or its psychological (sp?) imbalance  
.

Matt
 
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