Doubles and Bc's

[Rooster1]

This might be a dumb question, but I really don't know.
A friend and I were discussing this question. I have never seen doubles on a regular jacket style bc, always on wings. Do divers use regular jacket style bc's with doubles??

 

[trymixdiver]

Before i knew about backplates and a harness i made the big mistake of attaching 2 alum 80's to my jack style BC. I was diving in Lake Mohave off a pontune (sp) boat. We dropped into 145 to recover an anchor lost by the people who lived in the cabin next door. Before we even located the anchor my jacket style BC boke and i ended up finishing the dive carrying my doubles. Lucky for me i only had a short safety stop to do.
Needless to say i discovered a Diverite ABS backplate, harness and wings configuration upon some inquiry after my return.

Andy

I never recovered the anchor

 

[jetblast00]

Zeagle rangers are designed to do both singles and doubles. But, with only 44lbs of lift, it's only suitable for Aluminum doubles, not steel.
The Zeagle tech is pretty much the same as the ranger, but has some more D-rings and 65lbs of lift.
The Dive-rite Transpac II is also used for doubles, but while not a hard backplate, it does takes differnent wings

 

[Jonathan]

I have seen it on Scubapro Glide 2000 a few years back - it looked like a bit of a phaf! They were not manifiolded or even banded. What's more the diver in question worked for a dive shop so I don't know why she did not bother getting a wing and bands as I am sure she could have got them at cost.

each to their own I guess....

Jonathan

 

[WreckWriter]

Way back when, I guess 1993-4 or so, before harnesses and wings were commonly available, I dived for years with double 80s on a ScubaPro "Double Black" jacket BC. They were manifolded, and banded. As I recall the BC had about 45 lbs of lift, which was more than plenty.

Although I don't recommend this based on the better systems that are available now, it worked very well for me. It is possible, maybe even probable, that the old ScubaPro jackets were better made than today's recreational BCs.

Tom

 

[Walter]

I've made the majority of my dives in this fashion since 1989. I mounted twined slim 72's on a Scubapro double black using a non isolation manifold. I put them together (not including the manifold) for about $5. It is a very sturdy setup and has never given me any problems. The bladder gave up the ghost last year, so I kept the hardware and put on a new bladder (the sport is almost identical).

The reason most doubles are on wings is because people rarely think outside the box.

 

[WreckWriter]

For me the reasons for doing it that way were as follows:

1- Financial. At the time I was running dive boats in Key Largo for a living. Pay was decent at best. Rather than buy new gear I used what I had as much as possible.

2- Wing setups may have existed but they were certainly not commercially common. The more common doubles setup was a plastic backpack and a horsecollar BC (how many have been diving long enough to remember using those??). The jacket arrangement was a significant upgrade over that.

At this point, although I do feel that using doubles (aluminums, NOT large steels) with a Scubapro jacket is safe and viable, I'm a full convert to the backplate and wings system.

Tom

 

[scubafinatic]

I recently bought a doubles manifold with the intentions of using doubles.I have a pair of steel 72's and a Zeagle Ranger BC.I then proceeded to research the advice of others and and have found a couple of things that may or maynot be of concern.1st;some divers say that the use of double steel becomes a bouyancy issue and that the use of steel doubles isnt advised unless using a dry suit.I went to my LDS and spoke to them and they reminded me of the fact that if you remember ,people have been using double steel almost since the advent of scuba without either BC's or dry suits and that the only reason they could concieve of a person being concecrned about dry suit versus rubber is that in the event something went wrong that having to dump thier high dollar equipment in the for an emergency ascent and losing it as opposed to having the added bouyancy to overcome the negativity inherent in steel doubles seems to be the reasoning behind this.he advised me to go for it.just an added note;I am going to get the bigger bladder offered by zeagle and that is probably it and damn the torpedoes full speed ahead! but if anybody has another reason and can back the reasoning by imperical evidence i welcome it as things can be live or die as we all know and researching new configurations is a must i believe.i appreciate the opportunity this forum allows and with that in mind welcome any comments.thanks all

 

[pescador775]

SF, your LDS guy appears to be very knowledgable. The double 72's have near ideal trim for most diving. If diving a dry suit, it is a convenience to have heavier tanks or a back plate but not necessary since some vests accept trim weight. Don't go overboard on the vest buoyancy, 35 pounds is plenty, especially for the 72's.

There are numerous misconceptions and an extreme amount of hand wringing about buoyancy issues, more than one would reasonably expect. I guess it's a hot topic because of the instructors. Are they teaching "buoyancy" classes now? That would explain part of it. The formulas and calculations that I am seeing, that are causing some confusion and a lot of controversy, must have come from them.

Don't overweight, adjust for neutral trim at 15 feet with near empty tanks, and trust your BC for everything else. Carry about 1/2-2/3 of your ballast on a belt or other "ditchable" method. There is a range of values because your buoyancy is not constant (air consumption). It's mostly trial and error but if you are of average size and are wearing a full winter wet suit, you probably should start off with about 15 pounds of lead and work from there. For fresh water, there is a 3% difference. For example, if you and your kit displace 200 pounds of water, you will need about 5-6 pounds less of ballast in fresh water.

Pesky

 

[roakey]

Originally posted by scubafinatic
I am going to get the bigger bladder offered by zeagle and that is probably it and damn the torpedoes full speed ahead!

Why bother asking if this is your attitude? Statements like this torque me off, but in the hopes of saving yet another diver from a bad LDS, here goes...

Please, feel free to go ahead and not learn from those that have gone before you, many making the same mistakes that you’re about to make.

A number of points about your post:

1. First thing to do is realize that Arkansas is not the technical diving Mecca of the free world, and though maybe some staff does some technical diving, their focus and expertise is in recreational diving. The reason so many aspiring technical divers end up with Ranges (and unfortunately selling the later) is because the only “technical” line recreational shops carry is Zeagle. Problem is, Zeagle is merely “Fashion Tek.”

2. Your shop won’t recommend anything they don’t sell no matter how much this is a disservice to the customer, and being mostly a recreational shop they won’t offer much true technical equipment.

3. No matter what they tell you, a Ranger will not stabilize the additional weight of doubles very well. Oh, it’ll keep them on your back, but they’ll slop around. Doesn’t make for a fun dive.

4. There’s no good way to mount a canister light to a Ranger.

5. The Ranger comes with a 44-pound lift wing. I dive double 104s with a canister light in fresh water with a 45-pound lift wing. If the shop is telling you that you need a larger wing, ESPECIALLY with 72s it tells me right then and there that they’re totally clueless.

6. The reason you don’t dive steels and wetsuit is because if you have the correct kind of BC for diving doubles it’ll give you little or no ditchable weight. Now, combining the 72s with an inappropriate choice for BC, you’ll probably be able to get away with what you’re proposing, since you’ll probably need some ditchable weight no matter what. Bottom line is that with a wet suit you need to be able to ditch enough weight in order to swim your rig up. Same with a dry suit, but you have the additional option of being able to use the dry suit as a BC in an emergency.

I have no idea what you’re referring to when you talk about “dumping high-dollar equipment.”

If you buy your bigger wing and really get into technical diving, come back and tell us how much you lost by selling your Ranger and wings on eBay versus getting a BP from the get-go.

Remember that folks here are not making our living from selling equipment to you whereas your shop is. Who is more likely to steer you to inappropriate gear to line their pockets?

Roak

Ps. Your dual 72s will swing about 11 pounds from full to empty, 10 pounds if they no longer have their + rating.