Twin cylinders??

[Schwob]

I dive a DSS backplate and wing

Side question if I may:
Those DSS BPs cost a proud bunch, but come in sizes. What size worked for you, how did you figure "your size" (did you try two sizes and then decided or how did you figure)?

For you, is it worth it compared to a standard size? Why, what difference (other than maybe a little extra weight in SS and not in lead) does it make to you?

E.g. I am just 6' but have a longer back and shorter legs than typical, maybe a back like a normal legged 6'3" posdibly 6'4" guy... not sure entirely (I seem taller seated than standing)... and it serms the regular (rather affordable BPs, like DGX) want me to have the hip loop of the harness closer to the belly button than to the hip or run just quite down in the front to make it below my "frontal mass of pure steeled belly shaped core muscle" .... or I just really have the plate too high... just not sure yet...

 

[2airishuman]

Side question if I may:
Those DSS BPs cost a proud bunch, but come in sizes. What size worked for you, how did you figure "your size" (did you try two sizes and then decided or how did you figure)?

For you, is it worth it compared to a standard size? Why, what difference (other than maybe a little extra weight in SS and not in lead) does it make to you?

E.g. I am just 6' but have a longer back and shorter legs than typical, maybe a back like a normal legged 6'3" posdibly 6'4" guy... not sure entirely (I seem taller seated than standing)... and it serms the regular (rather affordable BPs, like DGX) want me to have the hip loop of the harness closer to the belly button than to the hip or run just quite down in the front to make it below my "frontal mass of pure steeled belly shaped core muscle" .... or I just really have the plate too high... just not sure yet...

Mine is a large, which I figured would fit based on the sizing guidance on DSS' web site. I bought it used from another diver on ebay. That purchase included the weight plates. I have since purchased two additional used DSS wings from other divers, and a Halcyon wing. My daughter has a Dive Rite backplate, which works OK, but I had to elongate one of the camband slots to get it to work with a DSS wing without using a single-tank adapter.

I thought the availability of the weight plates was a big deal at the time I made the purchase. While they are helpful in certain narrow situations, I don't find that I use them as often as I anticipated.

 

[Schwob]

Mine is a large, which I figured would fit based on the sizing guidance on DSS' web site. I bought it used from another diver on ebay. That purchase included the weight plates. I have since purchased two additional used DSS wings from other divers, and a Halcyon wing. My daughter has a Dive Rite backplate, which works OK, but I had to elongate one of the camband slots to get it to work with a DSS wing without using a single-tank adapter.

I thought the availability of the weight plates was a big deal at the time I made the purchase. While they are helpful in certain narrow situations, I don't find that I use them as often as I anticipated.

Thanks!

 

[blac86]

Well the two main multi-task setups are back mounted doubles or sidemounted tanks. Before we delve into that I'd like to echo what has been stated in this thread, as you gain more experience your SAC rate will get better. New divers are often under insulated and overweighted, a combination that can kill efficiency. Also effective breathing underwater is very different from aerobic breathing or from playing a wind instrument. If you take big gulping deep breaths you'll not utilize all the o2 in the breath before you exhale it . Try to stick in the range of 33% full lungs to 80% full lungs. You probably also do more arm and body movement than you realize as a new diver.

Backounted doubles is typically two tanks of the same size connected by an isolator manifold and worn on the back. The manifolds mean either reg breathes out of both tanks, giving you a double sized air supply.

Sidemounted doubles involve slinging one tank on each side of your body, each with independent regulators. This will double you total volume but each tank is independent as opposed to backounted doubles.

 

[2airishuman]

But then why HP120s and not HP133s? The latter seem to make more sense as long dive nitroc singles with ponies and I don't see why they would be worth as doubles in significant ways.

The 120s have the same diameter as AL80s. If you're diving single cylinders, that's a good thing, because then the cylinder will fit in the same places an AL80 (in racks on boats, particularly), and will use the same length cambands.

But I hear / read that neither is not a good choice for SM at least for most (don't really know so - yet).
It seems there is a consensus (my not yet fully formed interpretation) that LPs like 95s especially, maybe also 108s seem to be a great choce across the board for mid to large size people if you can get cave fills.

LP95 has the same size shape buoyancy and weight as an HP117
LP108 has the same size shape buoyancy and weight as an HP130

No reason to get LP95 or LP108 instead of HP117 and HP130 in this day and age other than perhaps cost.

Anyway if I want to plan for vacation dives where I will be stuck with AL 80s (or where that is just convenient and all I want is the functionality and duty of a pony AND 40% more gas than e.g. my son on deeper rec. dives and say 30% more on shallower ones (which go long enough he won't mind if It's shortened by 5 minutes. I think I can work that out with 3 AL 80s... One serving as the Pony AND part of the gas plan for both dives with 1000 to 1200 PSI planned to be taken out of it the first (deeper) dive (rest is contingency only for that dive) and then between 800 and 1000 PSI to be taken from it (pending what was taken out the first) during the shallower second dive and 1kpsi staying in for contingency (775 PSI in a 77.4 cuft AL 80 is the same gas as 3000 PSI in an AL 19 certainly enough contingency for the shallower dive (did the math for me)).
So in that case I would need to bring 3 tanks for a two dive boat trip or a two dive shore dive trip (pre refill) (of course 4 won't hurt if an ootion). same diffetence if SM or slung "managed pony" (or independent doubles for that matter).

Again the problem with all this is that you have to find a dive op that will go along with it. I would expect that most will not go along with it. Most boats will tolerate a pony up to AL40 with the understanding that it is for emergency use only.

One thing is for sure: The AL100s you can rent / get in many warm water destinations are a bit problematic in that (at least Luxfer S100s) they hold 100cf at 3300 PSI , but so far I have only gotten them filled to around 3000PSI, because that's what "they" run at for their auto shutoffs and "they" dont want to change their setting (was told that even at Rainbow Reef, really dislike to beg...) or flat out deny that 3300 PSI and not 3000 is "full", so they in practise for me so far are just a 10% boost... ... slightly better actually than the HP100 an LOB last year would just not fill to north of 3000PSI, feigning ignorance and insisting on it being full at 3000PSI, not 3400PSI...
Live and learn...

That is a real problem, yes. You have to call around and find operators that have HP steels. Many operators have HP100s, some have HP120s, depends on the location. Some only have HP cylinders in DIN or only with nitrox fills or both.

 

[Schwob]

The 120s have the same diameter as AL80s. If you're diving single cylinders, that's a good thing, because then the cylinder will fit in the same places an AL80 (in racks on boats, particularly), and will use the same length cambands.



LP95 has the same size shape buoyancy and weight as an HP117
LP108 has the same size shape buoyancy and weight as an HP130

No reason to get LP95 or LP108 instead of HP117 and HP130 in this day and age other than perhaps cost.



Again the problem with all this is that you have to find a dive op that will go along with it. I would expect that most will not go along with it. Most boats will tolerate a pony up to AL40 with the understanding that it is for emergency use only.



That is a real problem, yes. You have to call around and find operators that have HP steels. Many operators have HP100s, some have HP120s, depends on the location. Some only have HP cylinders in DIN or only with nitrox fills or both.

Yep.
edit: Yep to all, including the potentlial trouble about being sure the operator would go along with the slung Al80 as part of the gas plan... - strangely, presumably not a problem so if it's side mount and the operator goes along with that... (and I don't mind bringing 4 instead of 3 tanks, still my call how many i use then).

BTW, generally, if the operator is a larger operation, how do you make sure anything agreed on during a call ahead actually then will fly at the dock or on the boat, with entirely someone else being the gatekeeper?

 

[Cap335]

confirm your conversion by email

 

[Akimbo]

... He adopted side mount early on just to have a fighting chance of staying down. This is certainly an option for the travelling diver... you supply the harness, regs, cam bands etc, and all you need are the tanks...

I helped a friend build a backmount rig for travel. It worked with whatever he could rent for an independent doubles rig. We bolted two STAs together with plastic block spacers so the STAs were back to back. Two cam bands/side held the tanks together. It worked better than expected. It broke down pretty compact for travel. Sorry, I didn't take any photos but I could probably draw it up if anyone is interested.

 

[HantsDiver]

As someone else has said: twindies are the best option for travel if you go down that route. It's just twin independent singles.

Scubapro make something call a bibo which can attach the cylinders together. Although I've never tried it so can't say it it's any good.

 

[Akimbo]

Scubapro make something call a bibo which can attach the cylinders together.

Thanks, and the price isn't bad: Scubapro Bibo Kit | Jackson-Sports.com