Backplate/wing: set-up questions concerning buckle and weights.

[tbone1004]

so all of those arguments say to put it in which forum? It absolutely belongs in basic because it is a fundamentally basic concept of diving. Be neutral. Even PADI is now enforcing everything be done neutrally buoyant. Can't put it in advanced because it isn't an advanced diving topic, it is one of arguably the most basic concepts of diving aside from don't hold your breath while ascending.
I said you need to dive a balanced rig, I said with a balanced rig you do not need ditchable weight. I stand by that, if people are going to be morons and overweight themselves, then they are not diving a balanced rig. If you dive with ditchable weights WITH the intent to ditch them, I would urge you to make sure that what you choose to ditch makes you neutrally buoyant instead of positively buoyant because an AGE will kill you.

My students are all required to retrieve a 10lb brick from the bottom of the pool on day 1 and swim it back to the side. This is something that has been done in middle school swim lessons for decades and anyone who is scuba diving should be able to do that. 10lbs is roughly the full compression of a 3mm wetsuit and the gas in an al80 and the amount that you should be negative in that configuration when at say 100ft. They have to do that in a bathing suit and nothing else. It's not hard. If you have fins on, it's a cake walk.
A 7mm suit with an HP130 is roughly 24lbs negative combined assuming the suit is fully compressed. You can compensate for about 6lbs of negative buoyancy with your lungs, and you can can easily swim the other 18lbs up with fins on. Once you get to the surface, assuming you haven't actually breathed anything, you're only 10lbs negative from the tank. You know you can swim around barefoot with a 10lb brick, and you have fins on, so while certainly unpleasant, you can stay at the surface to kick somewhere if you had to.
I'm not advocating to have no ditchable lead. If I'm diving a 7mm suit with a HP130 in the open ocean, I'm not going to use a weighted STA or weight plates to offset the 14lbs of positive buoyancy in the suit. I'm going to use a SS plate with the tank to take up 8 of it, and the other 6 is going to be on a weight belt. If stuff really hits the fan and I can't use my safety sausage or lift bag to stay at the surface, I'll ditch the belt and breathe the tank down so I'm floaty. If I'm shore diving though, I'd rather use a weighted STA or plates and not deal with a belt.

You guys are taking poor training as an excuse for poor diving methodology and that's a cop out and what is truly wrong with the industry right now. It is an equipment solution to a skills problem and I will not accept laziness and ignorance as excuses for being negligently overweight. Overweighting students is negligence, nothing else, and saying that we can't talk about openly is inexcusable.

TLDR, I said clearly that if you are diving a balanced rig, you don't NEED ditchable weight. If you don't know what either of those things is, I suggest you get your head out of the sand and figure it out before you go to the pearly gates for your own stupidity

 

[Roger Hobden]

I would tend to agree with tbone1004.

Beginner divers like myself come on SB to get thoughtful advice, which they will then analyze to see how much of this advice is applicable to their setting. Setting would include type of dive environment (lakes vs oceans), but also available local dive shops, equipment, certifying agencies, local instructors, etc.

Most dive agencies, probably all, recommend to never dive beyond your training, including the equipment you were certified with.

I doubt very much newer divers will start bolting weights on their BC without first having a thorough discussion about the pros and cons of this practice with a an Instructor in their area who knows their training, their gear, and their diving conditions.

 

[johndiver999]

Good to see tbone has now changed his comment
About never dropping lead at depth.

I agree with a good bit of what he said, but I am skeptical of the assertion that a typical diver could kick up 18 lbs negative (Well actually it is 24 lbs in his example) and maintain a good ascent rate from 100 feet or something.

Does anyone have video of anyone ever doing that? I think it would be interesting.

 

[MichaelMc]

@tbone1004, Diving neutral and skills neutral is separate from properly weighted or having ditchable. I don't know a better forum. I think not all divers could do your 10 lb. brick test, so the swim up part of balanced rig becomes more finely measured.

But my concern is messaging and redundancy.

Keeping a modest amount ditchable, 4-6 lb., is a useful safeguard. Which you seem to express. And does not in any way impact diving a balanced rig, assuming the ballast was required. Yes, balanced means you do not need ditchable. But I do not need my SPG or my secondary. If I screw up, say by changing tank types without thinking, then some ditchable is a hedge against that mistake. Ideally by letting me adjust my weighting before jumping in, if at some reduction to my remaining ditchable hedge.

For messaging, hearing:
A) 'Balanced is incompatible with ditchable', full stop, is one thing. And wrong by the definition below from the other thread, so it's a phrase that should not be used, IMO.
B) 'Balanced means not needing ditchable', full stop, is more accurate, but incomplete by that same definition, as that definition provides for partial ditching at depth if needed to swim up.
C) 'Balanced means not needing ditchable, but some ditchable is prudent.' seems a better message. As a hedge if the swim up was not as strong that day, or against weighting mistakes.

You seem to object to them thinking having ditchable is prudent (a gear/method thing) because they might interpret that as they should ditch lots of weight at depth to get up (a training failure).

I doubt very much newer divers will start bolting weights on their BC without first having a thorough discussion about the pros and cons of this practice with a an Instructor in their area who knows their training, their gear, and their diving conditions.

You may have missed the new members we had that asked very basic questions about proper weighting and then went off really happy they could put all their weight on their back plate -- not a prudent approach IMO when you have other options.

ETA: From the other thread, a balanced rig is:

A) Weighted so that you're neutral at 15' with no gas in your BC and near empty tanks
B) Light enough to allow you to swim to the surface in event of a BC failure with full tanks

If you need to add so much weight to accomplish A that you can no longer do B, some of that weight needs to be ditchable so that you can accomplish B.

If your tank choice precludes you from doing B (heavy steel doubles), then you need a way to *immediately* establish positive buoyancy (drysuit). Fiddling with lift bags and trying to orally inflate a double bladder wing is *not* a viable solution when you're plunging toward the bottom.

I am happy for any more authoritative definition of balanced rig, this is just what one person said it was, but that is the one I have seen here. Note the middle part about ditchable. Now, it does provide only one case for ditchable, unable to swim up otherwise. I'm not sure if excluding the ditchable option in other cases is the intent or not, or if this is meant to be read that exactly.

 

[tbone1004]

@MichaelMc what @PfcAJ holds true, but in recreational diving, you should never have an issue doing A.
What it doesn't mean is that if you have the ability to use a SS backplate with no additional lead because you're weighted properly that you choose to use a neutrally buoyant plate and use ditchable lead. That's stupid, and yes I will stand by that.
If you can't retrieve a 10lb brick, then I am sorry but you are not fit to dive and I would argue that you would be unable to pass a diving physical. It's not a hard skill, and yes 10 year olds do it on a regular basis in swimming lessons...

 

[MichaelMc]

What it doesn't mean is that if you have the ability to use a SS backplate with no additional lead because you're weighted properly that you choose to use a neutrally buoyant plate and use ditchable lead. That's stupid, and yes I will stand by that.

Why is it stupid?

You said ashore you would use steel plus weigh plates. Ok, lets call that combo your plate.

But you said in open ocean you would use a steel plate (no weight plates) and tank but put the rest, 8 lb., on a belt. How is that different from the neutral (less negative) plate and ditchable?

Is it just needing two plates? If I got my AL plate in the tropics, then dive cold and add the weight as ditchable instead of as a ST plate, or weight plates, is that stupid?

 

[jlcnuke]

@MichaelMc what @PfcAJ holds true, but in recreational diving, you should never have an issue doing A.
What it doesn't mean is that if you have the ability to use a SS backplate with no additional lead because you're weighted properly that you choose to use a neutrally buoyant plate and use ditchable lead. That's stupid, and yes I will stand by that.
If you can't retrieve a 10lb brick, then I am sorry but you are not fit to dive and I would argue that you would be unable to pass a diving physical. It's not a hard skill, and yes 10 year olds do it on a regular basis in swimming lessons...

And here comes the crux of the issue I've had with your statements throughout this thread... YOU aren't giving everyone their dive physicals. YOU don't actually get to determine if every diver out there is fit to dive or not. YOU can, however, provide them with confusing information that might harm them because they didn't get their dive training from YOU with YOUR standards and YOUR lessons. Nope, instead, they got told that the 18 lbs they wore with no exposure suit on their OW dive class in the tropics was perfect weighting for them, so they took the standard recommendations and upped when they shifted to a 7mm for that local dive back home and now can't swim up with the failed BC and 25+ lbs of lead, but they bolted it right on because they thought that's what you meant when you said weight shouldn't be ditchable as that makes you a bad diver and they don't want to be a bad diver.

I'd honestly love it if you'd go through a modern PADI etc OW class in a "regular place" that a typical recreational diver does them and see just how different your idea of what is "basic" knowledge is from what is ACTUALLY taught to the people showing up here with a "basic knowledge". Heck, even you experts can't seem to agree, since Andy Davis (a different tech instructor) is out there telling us that "one major safey benefit of the balanced rig is that it enables the diver to identify the minimum amount of ditchable weight they need to maintain" while you're telling us that "You do not get to use "ditchable weights" as the concept is incompatible with a balanced rig", polar opposites as far as I can tell, so who could blame a "basic" diver if they're getting confused. Of course, I then read that you're okay with ditchable weights, as long as you ditch them on the surface... but then Andy's blog there explains how to figure out how much ditchable weight you should have and it turns out it's the difference between what you could ascend with comfortably and what you need to be perfectly weighted... indicating it would be ditched at depth so you could swim up....

Of course, the PADI OW, AOW, PPB, and deep courses combined mention the term "balanced rig" zero times so I would be absolutely shocked if most rec divers had ever heard the term, much less thought to try and figure out what it was supposed to mean.

So yeah, having not taken any GUE courses or done tec dive courses etc, the information your stating conflicts with the training I've had, doesn't seem to be so "basic" when it changes and appears to conflict with other instructors, etc... so maybe all that stuff could be covered by the experts and sorted out before piece-mealing stuff out here in the basic forum, that's all I'm saying.

 

[tbone1004]

@MichaelMc ss plate with no additional lead means you are at most 8lbs negative depending on the tank. Most you'd be able to put on a belt is about 4. That's not worth the hassle.
Using ditchable weights instead of integrating them to the rig is less ideal, but it comes back to what you're diving with that causes you to need that much lead.

@jlcnuke Andy's comment implies that you're able to wear lead. My double 104's are 20lbs negative empty. Even in a drysuit I don't need lead for those. I would only need extra lead if I was diving in truly cold water. Once you're doing that, you have redundant regulators, and redundant buoyancy so you aren't having to kick up a rig. In recreational diving, that comes back to what I said about 7mm farmerjohn's being unsafe suits to dive because they lose too much buoyancy at depth to be able to kick up and if you ditch weight, you won't be able to maintain a controlled ascent because you won't have enough ballast left to hold a safety stop or keep your ascent rate slow enough to minimize the risk of an embolism. DCS and AGE are bad.
You need to actually get into a quarry and try Andy's test. I think you'll be surprised at what you can actually kick to the surface.

While those courses don't mention "balanced rigs" they do discuss how to do weight checks. They're just largely ignored because the instructors are lazy and/or incompetent. They allow the students to move when doing weight checks, they don't wait until their breathing stabilizes, etc. As said above, you can keep a 10lb brick at the surface without fins on, you can cause at least a 6lb buoyancy swing just by breathing. That alone can lead to gross overweighting of divers because instructors are lazy and/or usually ignorant and competent.

What is done in the industry due to ignorance/laziness/incompetence does not mean that we should condone such behavior which is only going to allow that incompetence to continue.

If that conflicts with your training, you unfortunately had bad training, it's normal. It however, is VERY basic.

 

[PfcAJ]

@tbone1004, Diving neutral and skills neutral is separate from properly weighted or having ditchable. I don't know a better forum. I think not all divers could do your 10 lb. brick test, so the swim up part of balanced rig becomes more finely measured.

But my concern is messaging and redundancy.

Keeping a modest amount ditchable, 4-6 lb., is a useful safeguard. Which you seem to express. And does not in any way impact diving a balanced rig, assuming the ballast was required. Yes, balanced means you do not need ditchable. But I do not need my SPG or my secondary. If I screw up, say by changing tank types without thinking, then some ditchable is a hedge against that mistake. Ideally by letting me adjust my weighting before jumping in, if at some reduction to my remaining ditchable hedge.

For messaging, hearing:
A) 'Balanced is incompatible with ditchable', full stop, is one thing. And wrong by the definition below from the other thread, so it's a phrase that should not be used, IMO.
B) 'Balanced means not needing ditchable', full stop, is more accurate, but incomplete by that same definition, as that definition provides for partial ditching at depth if needed to swim up.
C) 'Balanced means not needing ditchable, but some ditchable is prudent.' seems a better message. As a hedge if the swim up was not as strong that day, or against weighting mistakes.

You seem to object to them thinking having ditchable is prudent (a gear/method thing) because they might interpret that as they should ditch lots of weight at depth to get up (a training failure).


You may have missed the new members we had that asked very basic questions about proper weighting and then went off really happy they could put all their weight on their back plate -- not a prudent approach IMO when you have other options.

ETA: From the other thread, a balanced rig is:

I am happy for any more authoritative definition of balanced rig, this is just what one person said it was, but that is the one I have seen here. Note the middle part about ditchable. Now, it does provide only one case for ditchable, unable to swim up otherwise. I'm not sure if excluding the ditchable option in other cases is the intent or not, or if this is meant to be read that exactly.

If you need to add weight to be neutral at 15’, it *can* be ditchable, but it doesn’t *need* to be unless you cant swim it up.

As for using a light plate and adding weight, that’s totally fine. I don’t drag a steel plate down to the Cayman Islands. I bring my nice light weight aluminum plate. I put some weights in the cam band pouches. If I wore a wetsuit (like I do from time to time in Florida) some weight goes on a belt so it’s ditchable.

As long as you can get to a point where you can kick your feetsies and get to the surface, how you get there is pretty secondary in most cases so long as ditching doesn’t result in being out of control. You never want to be out of control.

 

[MichaelMc]

@MichaelMc ss plate with no additional lead means you are at most 8lbs negative depending on the tank. Most you'd be able to put on a belt is about 4. That's not worth the hassle.
Using ditchable weights instead of integrating them to the rig is less ideal, but it comes back to what you're diving with that causes you to need that much lead.

I agree that 4 lb. is of small benefit if properly balanced. I disagree with disallowing it if desired. Its cost is light and it adds a safety margin. I think saying 'balanced is incompatible with ditchable' will cause problems for divers. And you carried weight ditchable. You do not seem to even disagree on naming ditchable as a benefit of it, in the case of stuff really hits the fan.

@PfcAJ's summary above seems in line with my thoughts.

Not all divers are as fit as they should be, which I think pushes the some ditchable is, by necessity, appropriate more to the front.