elan
Contributor
Then an AL plate should work well for you if you switch to steel 100
How to pick a BP/W?
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Then an AL plate should work well for you if you switch to steel 100
rstofer
Contributor
So when you change from an Al 80 to a HP 100, you will be getting rid of 6# of lead. That doesn't leave a lot of ditchable weight (if any).
As you said, something to consider.
Why do you want to go to HP 100s? Do you run out of air before your run out of NDL? Certainly, a Nitrox diver will run out of air first at moderate depths.
You aren't going to be highly negative even with the HP 100. But what you probably can't do is get positive at the surface with a full tank and a broken wing.
One possibility is to wear a 1mm wetsuit. That ought to require a couple of pounds of ditchable weight. I don't know how warm that might feel in your local waters. Wish I did!
Richard
halocline
Contributor
Don't worry, you'll end up with a steel plate for your AL tank and a lightweight (AL or kydex if you go DSS) plate for your steel tank. You can probably use the same wing on both plates, it's not that much of an expense. Most BP/W divers end up with a couple of plates, it's the way of the world.
You could get an AL plate and use either camband pockets or a channel weight or even a (gasp) weighted STA if you're concerned about being overweighted. To me using a steel plate with an AL80 is a very nice way of countering the buoyancy of the tank so I tend to do that even if I'm a pound or two over the absolute minimum I might need to stay down.
Some Florida diving requires walking with the gear on. From the truck to the spring can be a third of a mile or more. Borrow or obtain a plate, wing, and harness; then put a 120 cu. ft. tank in it. Walk about half a mile (preferably out of the public eye) to determine if the straps dig into your shoulders. If no, you are good to go.
If your shoulders are rather broad, a one piece strap-harness may "cut into you". Ouch. Try a different harness, or perhaps look into a Dive Rite Trans Pac or similar.
Good luck with it.
If your shoulders are rather broad, a one piece strap-harness may "cut into you". Ouch. Try a different harness, or perhaps look into a Dive Rite Trans Pac or similar.
Good luck with it.
The OP asked, way back when, how to decide what BP/W setup to purchase, and whether an Air2 could be used with a backplate and wing. I'm hoping to go through some of the basic characteristics you might want to consider, and some ideas on how to evaluate them, without being particularly brand specific or voicing my own opinion (until the end).
1. Size. A backplate should fit so that the top of the plate is just at the bottom of the C7 spinous process (the large bump you feel at the bottom of your neck), and the bottom of the plate should sit so that the waist strap can run horizontally from the slots around the diver's waist at a comfortable height. The majority of people can pretty much manage this with a standard plate, but people who are very small or very tall are better off with specifically sized plates. Not all manufacturers make multiple sizes, so that's something to consider when choosing a brand.
2. Material. Plates come in stainless steel, aluminum, and plastics of various kinds. For cold water divers, the choice is generally easy -- a stainless steel plate becomes an integral part of your ballast, and improves your weight distribution for better trim. (This may not be true for doubles divers, who may need to use a light plate to move weight further down to combat head-heaviness.)
In warm water, the choice can be a little more confusing, and will depend in part on which tanks are used, and in part on the diver's personal choice regarding ditchable weight. With a thin wetsuit, a SS plate can be all the weight you need -- making a simple, streamlined and efficient rig, but without any weight to ditch, should you have a wing failure and have trouble getting buoyant at the surface. An SMB may be enough redundant buoyancy, or the diver may choose a lighter plate and a weight belt.
3. Bend. Plates vary in the angle of the bend. This is primarily an issue for people diving doubles, where shallow angles can make tanks with shorter bolts unusable. A shallow bend for a single tank diver puts the tank closer to the diver's back, which may be helpful in being able to reach one's valves (something which is a very good thing to be able to do).
4. Features. In this category, I include things like finish (poorly finished plates have burrs and can chew through harness webbing), camband slots (some plates have them, some don't, and the spacing is not standard), edge holes (some have them, some don't, and the number and spacing varies) bolt holes (some just have round ones, which requires the bolts to be precisely spaced; others have one or more elongated holes, making the use of various doubles setups a bit easier), and extras like the elastomeric inserts Deep Sea Supply uses to tension the straps.
5. Wing lift. Cool hardware_52 writes an excellent essay on determining required lift, but basically, your wing has to float your equipment at the surface, and compensate for the maximum lift your exposure protection can lose. People using single aluminum tanks don't have very negative gear to float, and are generally using thin exposure protection which doesn't lose much lift, so very small wings are appropriate. In cold water, the rig may have much more weight on it, with steel tanks, steel backplate, and possibly an STA or camband weights. In addition, the diver can lose much more lift from thick exposure protection. Thus larger wings are needed.
It is disadvantageous to buy more lift than you need, because a wider wing than you require will form large arcs above the tank ("taco-ing") where the air sits, making it very hard to vent. Inadequate lift is a safety hazard.
6. Wing materials. Most wings have an inner bladder of urethane or some other material, and an outer, fabric covering. But some are a coated fabric without an inner bladder. The thickness of the bladder can vary, and thin materials can be more prone to pinch flats, a common form of bladder leak. Outer fabrics vary, with some being extremely resistant to puncture, which might be an advantage to people doing wreck penetration and exposed to sharp and pointed surfaces. Many wings have zippers to access the inner bladder, but some do not, and require the wing to be sent back to the factory for bladder replacement.
7. Tank stabilization. Putting a round tank on the peak of the bend of a metal plate can result in a tank that wobbles. (Backplates were not originally developed for single tanks, but for doubles, which bolt to the plate so stability is not an issue.) One solution is to use a single tank adapter (STA) which can also be weighted, to add to the ballast on the diver's back. The problem is that an STA is an additional piece to purchase and to remember to attach, and puts the tank further off your back and makes it harder to reach. For systems without an STA, the wing is generally built with some kind of insert that stabilizes the tank. In my experience, these work quite well. Some people just put the cambands through the plate and cinch them down and say the tanks are stable enough.
8. Shape. Wings are basically either horseshoe shaped or doughnut shaped, depending on whether air can pass from one side to the other only at the top, or also at the bottom. Some people really argue for doughnut wings, feeling that they can't move air from one side of the wing to the other when they are horizontal with a horseshoe shape (where the air has to be moved up to the upper arc and across). This is important if one makes extensive use of the butt dump, because it dumps from only one side of the wing, and you can get lopsided lift. However, it is very easy to move air from side to side with a horseshoe, and Tobin's analysis above of the doughtnut wing (which he sells, by the way) has always seemed pretty persuasive to me.
Another consideration with shape is where you need lift. In doubles, I like a wing with a broad, square upper arc, so I can park some air there to help me avoid being head heavy. Rebreather divers sometimes like delta-shaped wings with a lot of lift by the hips. In a single tank, this is not so much of a consideration, because the diver has some flexibility on moving the tank up or down in the cambands to improve balance. Doubles are bolted, so there is less flexibility there.
9. Inflator. Inflators vary in the site of takeoff (some are in the middle of the top of the wing, some on one side), the length of the corrugated hose (and this is DEFINITELY a matter of preference, with some of us really liking them short and others finding short ones difficult to use), the flexibility and diameter of the corrugated hose, and the material of the inflator assembly itself. Some wing manufacturers allow you to order the length of corrugated hose that you want, and others just come the way they come. In addition, the way the inflator hose is secured to the wing can vary, and inflator hoses from different wings may not be interchangeable. Thus, if you want to use the Air2, it's worth either trying it on the wing you want to buy, or communicating with the manufacturer to make sure it will fit.
10. Price. Plates and wings can vary wildly in price, and sometimes there are amazing sales. In general, I'd say it's good to look at very inexpensive gear to see what you are giving up to get the price, and it's good to look at very expensive gear and see if there are any qualities that justify the price differential.
11. Customer service. Unless you get a puncture, there is not much maintenance to deal with with a wing, other than routine care. But some companies really help you carefully choose the equipment that will be right for YOU, and others just sell you gear. Some have better reputations for handling repairs than others. This kind of information shows up in the equipment threads.
I've tried to go through and cover all the facets of backplate rigs that I could think of, but I'll be very happy if anybody can think of something I've overlooked.
1. Size. A backplate should fit so that the top of the plate is just at the bottom of the C7 spinous process (the large bump you feel at the bottom of your neck), and the bottom of the plate should sit so that the waist strap can run horizontally from the slots around the diver's waist at a comfortable height. The majority of people can pretty much manage this with a standard plate, but people who are very small or very tall are better off with specifically sized plates. Not all manufacturers make multiple sizes, so that's something to consider when choosing a brand.
2. Material. Plates come in stainless steel, aluminum, and plastics of various kinds. For cold water divers, the choice is generally easy -- a stainless steel plate becomes an integral part of your ballast, and improves your weight distribution for better trim. (This may not be true for doubles divers, who may need to use a light plate to move weight further down to combat head-heaviness.)
In warm water, the choice can be a little more confusing, and will depend in part on which tanks are used, and in part on the diver's personal choice regarding ditchable weight. With a thin wetsuit, a SS plate can be all the weight you need -- making a simple, streamlined and efficient rig, but without any weight to ditch, should you have a wing failure and have trouble getting buoyant at the surface. An SMB may be enough redundant buoyancy, or the diver may choose a lighter plate and a weight belt.
3. Bend. Plates vary in the angle of the bend. This is primarily an issue for people diving doubles, where shallow angles can make tanks with shorter bolts unusable. A shallow bend for a single tank diver puts the tank closer to the diver's back, which may be helpful in being able to reach one's valves (something which is a very good thing to be able to do).
4. Features. In this category, I include things like finish (poorly finished plates have burrs and can chew through harness webbing), camband slots (some plates have them, some don't, and the spacing is not standard), edge holes (some have them, some don't, and the number and spacing varies) bolt holes (some just have round ones, which requires the bolts to be precisely spaced; others have one or more elongated holes, making the use of various doubles setups a bit easier), and extras like the elastomeric inserts Deep Sea Supply uses to tension the straps.
5. Wing lift. Cool hardware_52 writes an excellent essay on determining required lift, but basically, your wing has to float your equipment at the surface, and compensate for the maximum lift your exposure protection can lose. People using single aluminum tanks don't have very negative gear to float, and are generally using thin exposure protection which doesn't lose much lift, so very small wings are appropriate. In cold water, the rig may have much more weight on it, with steel tanks, steel backplate, and possibly an STA or camband weights. In addition, the diver can lose much more lift from thick exposure protection. Thus larger wings are needed.
It is disadvantageous to buy more lift than you need, because a wider wing than you require will form large arcs above the tank ("taco-ing") where the air sits, making it very hard to vent. Inadequate lift is a safety hazard.
6. Wing materials. Most wings have an inner bladder of urethane or some other material, and an outer, fabric covering. But some are a coated fabric without an inner bladder. The thickness of the bladder can vary, and thin materials can be more prone to pinch flats, a common form of bladder leak. Outer fabrics vary, with some being extremely resistant to puncture, which might be an advantage to people doing wreck penetration and exposed to sharp and pointed surfaces. Many wings have zippers to access the inner bladder, but some do not, and require the wing to be sent back to the factory for bladder replacement.
7. Tank stabilization. Putting a round tank on the peak of the bend of a metal plate can result in a tank that wobbles. (Backplates were not originally developed for single tanks, but for doubles, which bolt to the plate so stability is not an issue.) One solution is to use a single tank adapter (STA) which can also be weighted, to add to the ballast on the diver's back. The problem is that an STA is an additional piece to purchase and to remember to attach, and puts the tank further off your back and makes it harder to reach. For systems without an STA, the wing is generally built with some kind of insert that stabilizes the tank. In my experience, these work quite well. Some people just put the cambands through the plate and cinch them down and say the tanks are stable enough.
8. Shape. Wings are basically either horseshoe shaped or doughnut shaped, depending on whether air can pass from one side to the other only at the top, or also at the bottom. Some people really argue for doughnut wings, feeling that they can't move air from one side of the wing to the other when they are horizontal with a horseshoe shape (where the air has to be moved up to the upper arc and across). This is important if one makes extensive use of the butt dump, because it dumps from only one side of the wing, and you can get lopsided lift. However, it is very easy to move air from side to side with a horseshoe, and Tobin's analysis above of the doughtnut wing (which he sells, by the way) has always seemed pretty persuasive to me.
Another consideration with shape is where you need lift. In doubles, I like a wing with a broad, square upper arc, so I can park some air there to help me avoid being head heavy. Rebreather divers sometimes like delta-shaped wings with a lot of lift by the hips. In a single tank, this is not so much of a consideration, because the diver has some flexibility on moving the tank up or down in the cambands to improve balance. Doubles are bolted, so there is less flexibility there.
9. Inflator. Inflators vary in the site of takeoff (some are in the middle of the top of the wing, some on one side), the length of the corrugated hose (and this is DEFINITELY a matter of preference, with some of us really liking them short and others finding short ones difficult to use), the flexibility and diameter of the corrugated hose, and the material of the inflator assembly itself. Some wing manufacturers allow you to order the length of corrugated hose that you want, and others just come the way they come. In addition, the way the inflator hose is secured to the wing can vary, and inflator hoses from different wings may not be interchangeable. Thus, if you want to use the Air2, it's worth either trying it on the wing you want to buy, or communicating with the manufacturer to make sure it will fit.
10. Price. Plates and wings can vary wildly in price, and sometimes there are amazing sales. In general, I'd say it's good to look at very inexpensive gear to see what you are giving up to get the price, and it's good to look at very expensive gear and see if there are any qualities that justify the price differential.
11. Customer service. Unless you get a puncture, there is not much maintenance to deal with with a wing, other than routine care. But some companies really help you carefully choose the equipment that will be right for YOU, and others just sell you gear. Some have better reputations for handling repairs than others. This kind of information shows up in the equipment threads.
I've tried to go through and cover all the facets of backplate rigs that I could think of, but I'll be very happy if anybody can think of something I've overlooked.
JCR
Contributor
TSM, if I could sort out how to "Thank you" I would. However, your concise statement of the parameters of choosing a BPW helps me to sort out how to think about this. Well said and "thank you."
JR
sometimes the obvious is right in front or behind us....
JR
sometimes the obvious is right in front or behind us....
Last edited:
DevonDiver
N/A
Informative and concise post TS&M! That should be reposted as a sticky. 
From jtpwils:
Back to BP/W considerations. This may be a dumb question but I've noticed a lot of folks suggesting SS OR Aluminum wings, and diving SS plates with AL tanks or AL plates with Steel tanks but why is it (AL or SS) and not (AL or AL+STA)? The weight is still evenly distributed front to back but is in line with the tank rather than across the back. It would seem to me that you get the benefits of both types without having to have two different harnesses or refitting the harness if you only use an aluminum plate and add weight using other methods?
From rstofer:
In warm water (in my view, don't bother flaming me), in order to have any ditchable weight, the backplate should be something other than SS. Aluminum or kydex come to mind. Also, that steel tank becomes something of a liability because, if you do have a wing failure, you won't have any weight to ditch at the surface. You will always be negative. Yes, I like the Al 80 for warm water diving.
Heres my question:
Sometimes you are diving at a resort where they have only steel tanks. Many people, including the original poster, Oldnsalty, (and myself) might be overweighted with a stainless steel tank, even without any weight belt. So you would use your aluminum plate, plus ditchable weight. Then you (lucky SOB) get to have a second week of vacation on the same trip at a resort where they have only aluminum tanks (it happens!) As an alternative to switching over to the s/s plate that you packed due to the generous allowance the airlines are offering these days, (and using arthritic fingers to change over that hard double resin reinforced unboiled webbing!) jtpwils is suggesting alternatives like using an STA. As another alternative, Ive seen people use the same aluminum plate, use 3-4 pounds on a ditchable belt plus thread 3-4 pounds on the end of the tank cam bands and then hope it stays well velcroed down, throughout the dive including back roll entries and all. How secure is this in actual experience? Any real experiences to share?
FWIT, I have both plates, & have carried both, but are there viable/preferable alternatives?
Thanks.
Back to BP/W considerations. This may be a dumb question but I've noticed a lot of folks suggesting SS OR Aluminum wings, and diving SS plates with AL tanks or AL plates with Steel tanks but why is it (AL or SS) and not (AL or AL+STA)? The weight is still evenly distributed front to back but is in line with the tank rather than across the back. It would seem to me that you get the benefits of both types without having to have two different harnesses or refitting the harness if you only use an aluminum plate and add weight using other methods?
From rstofer:
In warm water (in my view, don't bother flaming me), in order to have any ditchable weight, the backplate should be something other than SS. Aluminum or kydex come to mind. Also, that steel tank becomes something of a liability because, if you do have a wing failure, you won't have any weight to ditch at the surface. You will always be negative. Yes, I like the Al 80 for warm water diving.
Heres my question:
Sometimes you are diving at a resort where they have only steel tanks. Many people, including the original poster, Oldnsalty, (and myself) might be overweighted with a stainless steel tank, even without any weight belt. So you would use your aluminum plate, plus ditchable weight. Then you (lucky SOB) get to have a second week of vacation on the same trip at a resort where they have only aluminum tanks (it happens!) As an alternative to switching over to the s/s plate that you packed due to the generous allowance the airlines are offering these days, (and using arthritic fingers to change over that hard double resin reinforced unboiled webbing!) jtpwils is suggesting alternatives like using an STA. As another alternative, Ive seen people use the same aluminum plate, use 3-4 pounds on a ditchable belt plus thread 3-4 pounds on the end of the tank cam bands and then hope it stays well velcroed down, throughout the dive including back roll entries and all. How secure is this in actual experience? Any real experiences to share?
FWIT, I have both plates, & have carried both, but are there viable/preferable alternatives?
Thanks.
cool_hardware52
Contributor
How 'bout to a little pre trip research and discover before you leave **what** tanks are available?
I always prefer a SS plate with buoyant tanks. That's one of the key advantages of a BP&W.
Sticking a +4 lbs "cork-like" al 80 on my back while using a near neutral (al or kydex backplate) then hanging 4-6 lbs around my waist basically defeats one of the key advantages of a BP&W.
Back plates and wings are a modular system, different plates, different wings etc.
Simply put this range of components exist because no one type of wing and plate is ideal everywhere.
That however never seems to dull the appetite for endless discussions about what BP&W will great for every climate, every exposure suit, every cylinder, doubles, singles, travel via hang glider, etc. etc.
I do recognize that most new BP&W buyers want to start with flexible a setup as possible.
Having fit many thousands of new BP&W users I can make a few broad statements:
If you are buying one wing it needs to sized for your coldest water application.
If you are buying one back plate in almost all cases a Stainless Steel plate is the best choice for both home and travel.
Tobin
"How 'bout to a little pre trip research and discover before you leave **what** tanks are available?"
I did. That's why I took both plates.
"Sticking a +4 lbs "cork-like" al 80 on my back while using a near neutral (al or kydex backplate) then hanging 4-6 lbs around my waist basically defeats one of the key advantages of a BP&W."
And
"If you are buying one back plate in almost all cases a Stainless Steel plate is the best choice for both home and travel."
I'm really happy with the ss plate and aluminum tanks and 4 pounds on my belt. But if I have a steel tank, what do you suggest?
I did. That's why I took both plates.
"Sticking a +4 lbs "cork-like" al 80 on my back while using a near neutral (al or kydex backplate) then hanging 4-6 lbs around my waist basically defeats one of the key advantages of a BP&W."
And
"If you are buying one back plate in almost all cases a Stainless Steel plate is the best choice for both home and travel."
I'm really happy with the ss plate and aluminum tanks and 4 pounds on my belt. But if I have a steel tank, what do you suggest?
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