Twinsets to accomodate different wing lift capacities

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Caveman

Contributor
Messages
93
Reaction score
14
Location
Southern Africa
# of dives
50 - 99
Hello all

I am at a bit of a crossroads here. I own two single bladder wings; one has 18kg lift and the other has 27kg lift. A Halcyon and a Dive Rite respectively. Both were bought second hand for a good price so as of yet, I still don't have my own twinset.

I would very much like to buy a 15L steel twinset. But while this would be perfectly adequate for a 27kg wing lift and then some, would it perhaps be overbearing on the 18kg wing? Would it maybe be in my best interest to rather buy a 12L twinset?

I know that other considerations factor in so I will save you the trouble of asking:

1. I dive with a 5mm Scubapro wetsuit (a drysuit will not factor into any of my decision making for at least the next 2 years)
2. I dive with Apeks RK3HD fins. Weighing in at about 3kg; so they are negatively buoyant.
3. I own both an aluminium and SS backplate (I can use whichever to accommodate the best combination).
4. I personally weigh around 78kg and maintaining.
5. While I don't own one yet, please put an AL80 deco bottle into consideration as well.

While I, like most aspiring technical divers, hope to own both a 12L and 15L twinset in good time, which would be the more feasible all rounder to start off with?

Thank you
 
I dive double 100s (12L) with a steel plate and a 40 pound (18kg) wing and I have plenty of extra buoyancy. Essentially my wing is never completely full and I typically wear an additional 4-8 pounds (about 2-4kg) If the 15L cylinders are only a few kg more I think you would be fine with the aluminum plate.

I would caution diving with this much weight without a drysuit for redundant buoyancy. If your wing fails (torn on shipwreck, etc.) you may be putting yourself in a dangerous situation trying to swim that much weight to the surface or maintain buoyancy during a safety / decompression stop.
 
As far as wing size, they will both work, the 18kg(40lb) for the 12L's and the 27kg(60lb) for the 15L's.

That being said, I'd be diving dry for the 15L's. Primarily because I disagree with redundant bladders and wetsuits when you get into more negatively buoyant rigs. It very quickly becomes a serious compromise, regardless of thermal considerations.

Also, are the RK3's 3kg negative in the water? That doesn't sound right to me. I had a pair of RK3's at work and they were neutral if not just a red one negative in fresh water. And for sure check out @rsingler 's Optimal Buoyancy Computer. It's a very slick thing.
 
Hello all

I am at a bit of a crossroads here. I own two single bladder wings; one has 18kg lift and the other has 27kg lift. A Halcyon and a Dive Rite respectively. Both were bought second hand for a good price so as of yet, I still don't have my own twinset.

I would very much like to buy a 15L steel twinset. But while this would be perfectly adequate for a 27kg wing lift and then some, would it perhaps be overbearing on the 18kg wing? Would it maybe be in my best interest to rather buy a 12L twinset?

I know that other considerations factor in so I will save you the trouble of asking:

1. I dive with a 5mm Scubapro wetsuit (a drysuit will not factor into any of my decision making for at least the next 2 years)
2. I dive with Apeks RK3HD fins. Weighing in at about 3kg; so they are negatively buoyant.
3. I own both an aluminium and SS backplate (I can use whichever to accommodate the best combination).
4. I personally weigh around 78kg and maintaining.
5. While I don't own one yet, please put an AL80 deco bottle into consideration as well.

While I, like most aspiring technical divers, hope to own both a 12L and 15L twinset in good time, which would be the more feasible all rounder to start off with?

Thank you

I don’t know anybody who is using a 15 L twinset. I guess the length is the same as a 12 liter tank long model, but the diameter is larger. Because of the dimensions nobody is using a 15L twinset here.

I use my 12L twinset for cavediving (sometimes also a bottom stage and deco stage) and wreckdiving max depth 51 meter. (Max 30 minutes of deco and one deco stage)

My double 18L twinset is filled with trimix and used for cave diving, max 2 bottom stages + 2 deco stages max depth 51 meter.

I would start with a 12L twinset.
 
Just for clarification, are these wings currently owned single tank wings? Or are they dou les wings? There is a difference in width.
 
Skip the 15L twinset since they are too short for the diameter, make you top heavy, and therefore trim bad.
If you need bigger doubles than 12s, I would go for a 18L twinset (although never in a wetsuit).

As for the wings: the 18kg wing is right for the 12L twinset (171mm tank diameter), for 204mm diameter tanks (15L, 18L, 20L) you need a larger wing.
 
As far as wing size, they will both work, the 18kg(40lb) for the 12L's and the 27kg(60lb) for the 15L's.

That being said, I'd be diving dry for the 15L's. Primarily because I disagree with redundant bladders and wetsuits when you get into more negatively buoyant rigs. It very quickly becomes a serious compromise, regardless of thermal considerations.

Also, are the RK3's 3kg negative in the water? That doesn't sound right to me. I had a pair of RK3's at work and they were neutral if not just a red one negative in fresh water. And for sure check out @rsingler 's Optimal Buoyancy Computer. It's a very slick thing.
Thank you! 12Ls are always an excellent twinset and is the preference of many divers. Regarding stage and deco bottles, if I am hauling a few of those over and above my twinset on an 18kg wing, could the load be a bit overbearing? Or due them being neutrally buoyant because of aluminum, are they not that much of a weight hindrance? No doubt I will learn the most ideal equipment mixing in good time; but it is good to know where to start.

Regarding the RK3 fins, my apologies for the confusion. The HDs are only a bit heavier than the normal RK3s. So partially negative at the most. I meant to say they weigh 3kg out of the water (including both. Not per each fin). I love using them.
 
Just for clarification, are these wings currently owned single tank wings? Or are they dou les wings? There is a difference in width.
The Halcyon Explorer and the Dive Rite Classic Wing. Both for doubles! :)
 
Also, are the RK3's 3kg negative in the water? That doesn't sound right to me. I had a pair of RK3's at work and they were neutral if not just a red one negative in fresh water. And for sure check out @rsingler 's Optimal Buoyancy Computer. It's a very slick thing.
Don't mean to hijack the thread, but just had a quick question/clarification: were you using the standard RK3s or the HD version? I'm asking because I'm considering getting a pair in the standard version and want fins that are neutral-ish in fresh water (a tiny bit positive or negative is fine, but more or less neutral).
 
https://www.shearwater.com/products/teric/

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