View Full Version : Pony or twins?
Hello All,
I'd like your opinions on which kit I should buy.
I've just finished my Sports Diver with around 20 dives under my belt, and clocking up around 6 dives per month. My club have been kind enough to lend me kit, even though I'm spending a small fortune each month! I've not yet bought a cylinder or regs's but, I don't think I can hold out for much longer.
As I see it, I have two options,
[1] Buy a 12L cylinder + regs and pony + regs - from ?650.
[2] Buy 10L twins + regs - from ?750.
I intend to dive quite a bit in future, at depths of upto 35 mts, and most club members dive with twins. However my wife has a big rollingpin, and I don't want to splash out on twins if I can avoid it. However taking the cheap option may bite me in the future.
Cheers.
David Walker
29-06-2005, 15:29
As I see it, I have two options,
[1] Buy a 12L cylinder + regs and pony + regs - from ?650.
[2] Buy 10L twins + regs - from ?750.
If you don't need twins yet, its probably best not to buy them yet, in my opinion. It means carrying a lot of extra weight that you don't need. If you think of the cost of a pony, most of it is in the regs, so as long as you buy decent regs (which you should anyway) then all you need to move to twins is a second cylinder. Depending on if you want to manifold them, if you get a tall 12l and a pony to start with, and when you are ready to move to twins just get a second 12l cylinder. And if you do want to manifold in future, get the cylinder with one of the MDE valves that are compatible with manifolds so you can just add that later.
Basically get the regs right, and the cylinders aren't a huge expense - especially if it was another year or two before you wanted to use twins, that cost of the pony spread out is nothing.
David
Alan Ewart
29-06-2005, 19:52
IMHO a 15L + Pony is adequate for diving to 35M. Twins mean a new skill set, valve shutdowns etc.
I have a 12L, a 15L, a pony and twin 12's. What I dive on depends on the type of diving I'm doing on a particular day. See if one of your mates will let you borrow twins to try in the pool. get a feel for them and see if you like them before investing. As a thought I never use twins when diving from a rib, too awkward getting back onto the boat. As always pro's & cons
Hello All,
I'd like your opinions on which kit I should buy.
I've just finished my Sports Diver with around 20 dives under my belt, and clocking up around 6 dives per month. My club have been kind enough to lend me kit, even though I'm spending a small fortune each month! I've not yet bought a cylinder or regs's but, I don't think I can hold out for much longer.
As I see it, I have two options,
[1] Buy a 12L cylinder + regs and pony + regs - from ?650.
[2] Buy 10L twins + regs - from ?750.
I intend to dive quite a bit in future, at depths of upto 35 mts, and most club members dive with twins. However my wife has a big rollingpin, and I don't want to splash out on twins if I can avoid it. However taking the cheap option may bite me in the future.
Cheers.
David Walker
29-06-2005, 22:50
As a thought I never use twins when diving from a rib, too awkward getting back onto the boat.
... although lots of people use them very successfully on RIBs, large and small. RIB diving certainly doesn't exclude twinsets, and never found it any more of a problem than a single + pony.
David
john williams
30-06-2005, 11:24
:=As a thought I never use twins when diving from a rib, too awkward getting back onto the boat.
... although lots of people use them very successfully on RIBs, large and small. RIB diving certainly doesn't exclude twinsets, and never found it any more of a problem than a single + pony.
David
I've even seen people diving with twinsets AND a pony from ribs (the pony fitted really neatly between the twins!)
What I could never fathom though was the strategy to use a twinset for two dives - I would always prefer to enter the water with enough gas for the dive (plus a reserve) - but why would you want to carry about the weight and bulk of enough gas for two dives on the first, or to enter the water with less than a full set on a second dive?
Why not just have a single cylinder (plus pony) for each dive?
Or smaller, neater, lighter twinsets - one filled between dives, or two (one for eac dive) if you prefer that configuration?
John
(who recognises that there is more than one way to do it correctly - but would like enlightenment!)
David Walker
30-06-2005, 12:48
What I could never fathom though was the strategy to use a twinset for two dives
Not sure about everyone, but I generally find that I will use a lot more gas (if it is available) on the first dive than the second. A typical example of a day's RIB diving in the Farnes with my club would be say the Somali first (~30m wreck) and then a dive on one of the actual islands later (variable 6~20m). With single cylinders that means a relatively short first dive, where as the second dive we'd probably come up long before we were anywhere near using all the air - so why not move that air from the second to the first dive?
Or smaller, neater, lighter twinsets - one filled between dives, or two (one for eac dive) if you prefer that configuration?
The problem with changing cylinder between dives (whether filling them or just carrying them and swapping them over) either means you're carrying lots of cylinders on the boat, or you have to return to shore between dives. Personally I find it far nicer to just stay out for the day - moor up on an island for lunch and then pootle around the corner for the second dive. Far nicer than heading back to shore, getting the boat in and tied up, off-loading cylinders, etc... Which means carrying the extra cylinders on the boat. Firstly, I can't afford two smaller twinsets even if I wanted to, which leaves singles. Apart from the problem of wanting more gas on the first dive than the second, if we're going to have two cylinders each on the boat then why not just take them in the water? Its no more effort, with RIB diving you don't have to walk miles around car parks in heavy kit, just rest it on the tubes and roll back. Lifting them back in I don't notice much difference between twin-12s and a 15+pony.
I have tried both ways, I was using a 12/15 + pony before last summer, and its these reasons that convinced my to change. Depending on the day and where we are it may be that we use most of the twinset on the first dive, and only have enough for a short shallow second dive, but if we had a good first dive then thats fine, thats what we do. If we're somewhere else then both dives may be very similar in depth/time/air consumption. Point is that the twinset gives the flexibility to enjoy the dives without the restrictions on time that a single cylinder gives - if you are really enjoying the first dive then you can choose to stay down a little longer, and eat a little into your air for the second dive.
Not everyone likes using twinsets, but I really don't find it any more of a burden than a single cylinder, especially for RIB diving. It only needs to be lifted from the bottle-rack onto the tubes, and then out of the water and back into the rack. If i did struggle then I might change my mind and go back to singles, but as it is, there are far more advantages of using them than disadvantages.
David
What I could never fathom though was the strategy to use a twinset for two dives - I would always prefer to enter the water with enough gas for the dive (plus a reserve) - but why would you want to carry about the weight and bulk of enough gas for two dives on the first, or to enter the water with less than a full set on a second dive?
Depends how you go about dive planning.
The dives that really interest me are large wrecks which tend to be found deeper than 30m. I stick with deepest dive first and will plan a bottom time to the extent of my gas or slack, whichever comes first. Already I can pretty much assume that I will be making mandatory stops so I will want to maintain a 1/3 reserve.
Few people want to sit out on the water for 7 hours waiting for the next slack (what's up with them). So the second dive is generally, what we can get while we are out there. Personally I don't see the point of going into deco for a mediocre dive. So the second dive is a shallow no stop dive and I can afford to be a little more agressive with the gas planning as there is no ceiling to consider.
So it comes down to what you said at the start. You need adequate gas and reserve for the dive. It happens that I don't need as much gas and reserve for the 2nd dive. I am quite happy to trade a little bottom time on a 2nd dive for the convenience of using what is left in the twinset. In fact it is not unusual for me to blow the gas on the 1st dive and sit out the 2nd savouring the earlier experience.
Add a deco stage cylinder into the equation and you end up with even more gas available in the twins for the second dive. The first decompression dive is planned allowing for the event of the deco stage not working when I come to use it. The gas requirement calc I use is,
((bottom + deco)/2) x 3
If the stage works, which it generally does, my twins have the deco gas, and the 1/3 deco gas reserve, intact for the second dive. Often this turns out to be more than would be available in a single 12.
Why not just have a single cylinder (plus pony) for each dive?
These days you do not have to be too adventurous to reach the limits of a single 15Ltr. Diving Nitrox within no decompression limits in the 25m to 35m range can put you on the edge of a 15s duration. Personal view, but if you consider a pony as a redundant reserve (a duplicate of the reserve in the main cylinder), 3Ltr is 1/3 of a 10Ltr, 1/4 of a 12Ltr and only 1/5 of a 15ltr. I don't consider a 1/5 reserve as adequate for much. A Y-Valve would offer better redundancy at the cost of a little bottom time.
Or smaller, neater, lighter twinsets - one filled between dives, or two (one for eac dive) if you prefer that configuration?
I own a set of 7 x 300s and a set of 12 x 232s. So I have the choice of which set fits the planned day better. Not everyone can justify that ammount of kit and so will have to equip for the worse case, where they are out for the day without a compressor, and put up with the inconvenience on other dives.
What I don't understand is why some divers contemplate twinsets at such an early stage. There are a mass of really good shallow water sites perfectly divable from club RHIBs using single cylinders. It took me several years before I got so bored of them that I followed the dark, cold, tedious and risky path of decompression and extended range. By adopting kit which is basically a PITA for small boat diving I think these people are missing out on some very enjoyable experiences. Perhaps even scareing themselves silly just because they have the kit to do so.
Ben Field
30-06-2005, 15:04
As I see it, I have two options,
[1] Buy a 12L cylinder + regs and pony + regs - from ?650.
[2] Buy 10L twins + regs - from ?750.
To be honest with "only" (not that its a bad thing) 20 dives in your logbook I think a single 12 or 15 is all you need, save the pony until you are doing 35+mtr diving ALL the time. It is NOT dangerous to dive to 35 or even deeper with just a single tank...
This way you can buy a pony or another 12 later on (after you've passed DL for example) and twin up then... spread the cost and spread the verbal you'll get back home for buying all that "useless dive crap" as my ex used to call it :-)
FWIW I now dive twins all the time (even, shock horror- off RIBs :) but thats just so I don't have to change config all the time and when instructing or taking photos its nice to hagve lots of gas and a nice stable setup.
Someone replied that they'd seen people dive off a RIB using a twinset AND a pony..... I've dived off a RIB with twin 15's, two 10ltr stages and an argon bottle... I don't see what boat you dive off has anything to do with what kit you take- whether its suitable for the dive you're about to do it all thats relevant.
BEN
Chris Cherrington
30-06-2005, 16:25
I don't much like ponys. They seem to be to be worst of all options.
As an alternative try looking at twin 7/7.5s. You are buying 2 regs anyway so this save the need for an octo.
If you buy cheap tanks there is little difference to a 12+3 if you buy expensive the manifold can be reused with new 10/12 cans later...
I wish I had been given this advice ages back - itt would have saved me loads of money.
Chris
As has been said in the other posts, this is dependent on the diving you are doing.
I was happy with a 12+3 up until I realisied more than half of my planned dives one season where below 35m!
I have always worked on the following assumptions
1. Anyone can swim from 20m up if they run out of air. The likelyhood of compulsary decompression is relatively low on air (37min no stop @ 21m), even lower on Nitrox.
Therefore a single 12l (10l etc) is sufficent.
2. Diving to 35m makes the swim to the surface more problamatic, & compulsary decompression may well be required (air = 14min no stop @ 36m).
Therefore a pony is a sensible addition.
3. Much below 36m a swimming ascent is not a practical option. Compulsary decompression is almost always required. Decompression on a 3 is unlikely to be sufficent.
Therefore a move to twinset diving needs to be considered.
It should be remembered that if a Y or H valve are being used, there is still only ONE air source. If you have a catastrophic air loss (freeflow) you are losing air from both the primary & secondary regulator air source, & MUST shut down the free flowing regulator immediately.
That said I often use a single 12 with a T - piece to fit the two first stages from the twinset (I don't need an additional set of regulators for a single or have to change hoses configurations). (Unlike the Y or H valve I can't shut one first stage down seperately). When I need redundancy I fit a pony to this arrangement.
In addition to depth considerations, redundancy is added if I'm teaching, including penetration in the dive profile & any other mitigating factor.
At this time I would suggest stay with the single, add the Pony, & do some diving.
In the longer term consider the Advanced Nitrox coarse (, the 3l can then also be used for carrying a Nitrox gas).
I hope this helps
Gareth
Why not get a 12 & a wing, do some more diving, then get another 12 & reg if you decide to go more tech? If you get a pony & reasonable quality reg as well, a pony cylinder can always be sold on e-bay. That way you are keeping your kit modular & flexible and develop it with your diving.
Must admit I went down the 15 & pony & BC route having not realised that a 12 & wing would be more practical to upgrade.
As it happens I tried a rebreather and went closed circuit.
So I?m glad I didn't rush into twins in the first place.
The 15 I use for training & the pony is now a bailout or additional diluent. I'll have to reconsider again when I get to CCR deco & trimix. The 15 will go in favour of independent twin 7s.
Just try and plan ahead as best as you can. If you are keen now, chances are 35m may end up being 45m + in a couple of years.
john williams
01-07-2005, 13:23
At this time I would suggest stay with the single, add the Pony, & do some diving.
In the longer term consider the Advanced Nitrox coarse (, the 3l can then also be used for carrying a Nitrox gas).
I hope this helps
Gareth
Thanks Gareth,
How much diving do you suggest that I do before adding a pony or considering a twinset?
Before you answer may I just tell you that in a few weeks I'll have been diving for 20 years and instructing for almost 15, I have logged many thousands of dives, I am an Advanced Nitrox Instructor, I've been an Advanced Instrutor for almost a decade and I teach on the ITS circuit.
Now...I'm certainly not bragging - nor am I getting at you...your comment just amused me ...and I thought I'd share the reason why!
I must confess however that I am not an avid wreckie. My degree is in Marine Biology and I prefer a good long pootle in the colourful vibrant shallows - where an hour underwater easily comes out of a 12l. I do occasionally dive deeper, to see corals, or to see what life has colonised a deeper wreck that is the objective for the day. I very rarely contemplate no-clear surface dives. So my single main cylinder with an air pony baleout/octo with a long hose on one side and a small deco pony on the other is as complicated as I like it to get.
I can also omit the deco pony if I'm not planning deco.
I do carry the air pony on nearly all o/w dives...but I do have a training set up with a true Octo that I use in the pool and at shallow OW training sites (including teaching OWIC and examining PIE events)
The points made by everyone have given me food for thought...and I hope will have given all those newbies your comments were aimed at reason to consider the real merits of buying kit this year for diving that they may not even get to years down the line in their diving careers.
Thanks for all the responses
John
;-))))
Sorry John
My comments were really targeted towards the original question.
" I have just completed my Sports Diver & done 20 dives ...."
However I believe the argument is still valid. If you are doing shallow recreational diving to a max of 20m, a single 12 is sufficent, a pony would be a personnel addition but not required.
Sub 20 - 35m,then I think a pony should be recommended, also if teaching, doing any form of penetration, solo diving etc.
Sub 35m then I think looking at a twinset becomes a sensible argument.
I certainly dived to 50m on a 12litre with 3litre pony in my early diving, I only changed to a twinset because the number of sub 40m dives was increasing.
I had hoped that I had pointed out that you should look at the kit in terms of the diving you are doing. It is not how long you have been diving, but more what type of diving.
I use a single 12 with pony quite often, its far more comfortable on shallow dives, especially shore diving or RIB diving. However once it starts to be around 30m I will normally take the twins (if diving from a boat), horses for coarses!
Safe Diving
Gareth
john williams
01-07-2005, 16:24
Sorry John
My comments were really targeted towards the original question.
" I have just completed my Sports Diver & done 20 dives ...."
However I believe the argument is still valid. If you are doing shallow recreational diving to a max of 20m, a single 12 is sufficent, a pony would be a personnel addition but not required.
Sub 20 - 35m,then I think a pony should be recommended, also if teaching, doing any form of penetration, solo diving etc.
Sub 35m then I think looking at a twinset becomes a sensible argument.
I certainly dived to 50m on a 12litre with 3litre pony in my early diving, I only changed to a twinset because the number of sub 40m dives was increasing.
I had hoped that I had pointed out that you should look at the kit in terms of the diving you are doing. It is not how long you have been diving, but more what type of diving.
I use a single 12 with pony quite often, its far more comfortable on shallow dives, especially shore diving or RIB diving. However once it starts to be around 30m I will normally take the twins (if diving from a boat), horses for coarses!
Safe Diving
Gareth
Couldn't agree more!
I REALLY was not getting at you...it just tickled me!
I think that this has been a really useful thread...and has been enhanced by your contribution.
As you say....
...safe diving
John
Thanks guys, a good mixture of opinions here, raising some good all round pro's and con's.
I think I'll hold off making the decision for the time being, and maybe use the cash to buy some of my own regs instead.
If diving 20+, I'll try to borrow a pony from the club, and if my diving tends to be deeper I'll review Pony or twins then.
Cheers.
:=As I see it, I have two options,
:=[1] Buy a 12L cylinder + regs and pony + regs - from ?650.
:=[2] Buy 10L twins + regs - from ?750.
To be honest with "only" (not that its a bad thing) 20 dives in your logbook I think a single 12 or 15 is all you need, save the pony until you are doing 35+mtr diving ALL the time. It is NOT dangerous to dive to 35 or even deeper with just a single tank...
This way you can buy a pony or another 12 later on (after you've passed DL for example) and twin up then... spread the cost and spread the verbal you'll get back home for buying all that "useless dive crap" as my ex used to call it :-)
FWIW I now dive twins all the time (even, shock horror- off RIBs :) but thats just so I don't have to change config all the time and when instructing or taking photos its nice to hagve lots of gas and a nice stable setup.
Someone replied that they'd seen people dive off a RIB using a twinset AND a pony..... I've dived off a RIB with twin 15's, two 10ltr stages and an argon bottle... I don't see what boat you dive off has anything to do with what kit you take- whether its suitable for the dive you're about to do it all thats relevant.
BEN
The big problem I see with twins off RIBs is they take up lots of space and weight (so you can't take as many divers) and then people seem to spend hours getting into them.
David Walker
07-07-2005, 11:02
The big problem I see with twins off RIBs is they take up lots of space and weight (so you can't take as many divers) and then people seem to spend hours getting into them.
Depends how you organise the diving. If you take enough cylinders out for the whole day (ie 2 each usually), which in my opinion is far preferable and makes for a much more relaxed day's diving, then they take up just as much space as twins (and in fact twinset is probably easier to manage since they're joined together and easier to secure).
Time getting into them I think might just be the people you know... I can't think of anyone in a twinset who takes a long time to get into it other than those who are slow to kit up in single tanks too. Speaking personally i'm almost always sat waiting for single-tank buddies to finish kitting up - and no, I don't think its anything at all to do with what kit they are using!
David
Ben Field
07-07-2005, 13:14
The big problem I see with twins off RIBs is they take up lots of space and weight (so you can't take as many divers) and then people seem to spend hours getting into them.
Twin 10's are smaller and lighter than a 15 and pony, obviously if you have a small RIB then its a no go but 5.5mtr RIB can take 6 or 7 divers with 15 to 20 cylinders easily, ours used to regularly.
If the owner of the twinset can't get into it on their own and as quickly as a single tank diver they need to rethink wether they should be diving twins, they are evidentally not capable of handling them.
BEN
Helen Butcher
09-07-2005, 21:44
Thanks guys, a good mixture of opinions here, raising some good all round pro's and con's.
Dunno if this is too late for you now, but i've done about the same number of dives, and am also currently doing my sports diver. I own my own kit, based on a BC, octopus/regs, and dumpy 12l, which i am very familiar and comfortable with.
I find twins (other than twin 7's, which don't gain me a lot of extra gas though they do feel nicely balanced) are too heavy and unwieldy and i find them difficult to get to grips with, whether manifolded or not. This might change once i decide to go deeper, or gain more experience, but i don't want to overload myself at this stage, as i'm still gaining experience of just diving.
A pony gives me a small independent air source, i find it easy to handle, doesn't add to much to my weight, and has been easy to adapt as an addition to my current BC/dumpy 12l based kit. It is also useful as an additional bail out even if i do decide to go for twins at some point. This is what ive opted for - I have adopted a degree of redundancy due to getting DCI in november - nothing to do with my diving or my buddies, but just makes you more aware of needing to be able to get out of potential life-threatening situations. I now carry a digital depth gauge as well as my dive computer, for example.
If u can 1) look at what the rest of your club are using, and ask them why (i know thats what youre doing here anyway, but if you do something that no-one else does you might be a bit isolated!)
2) try it out in the pool and the sea (on loan from your buddies if poss) to see what you feel comfortable with.
3) consider what you will be using/what diving you will be doing in the future. It might be shallow photography, for which twins might be a bit of an overload, or it might be wreck penetration/trimix for which single cylinder might not be adequate, or you might be thinking about a rebreather.
Hope that helps!
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