PADI OW and BPW

[Colliam7]

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A ScubaBoard Staff Message...

OK, folks, this thread has gone way off the rails, and way outside the bounds of the ToS.

It is CLOSED for further discussion, while a little clean-up is underway.

ADDENDUM: A number of off-topic / inappropriate posts have been deleted. Several other posts, which referenced those deleted posts, have been edited.

The thread is re-opened for discussion. Keep it CIVIL, and keep it ON TOPIC, which is: 'Is there some PADI rules that does not allowed a BPW to be used while teaching OW?

Bonus points is someone can also speak as to the applicability of BPW for HSA and OW course.'

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[Eric Sedletzky]

To bring the conversation back a bit, it is still ingrained in a number of instructors that BP/W or even just back inflate is going to kill you. I am a new assistant instructor, just helped with my first class. This particular instructor told me that a back inflate BCD would never work for teaching because it pushes you forward in the water. Mind you, he said this while I was reclining comfortably in the water with my back inflate... But nothing in standards says I couldn't teach in a BP/W for SSI, as established earlier in this thread

For my personal diving, I actually use a freedom plate (thanks @Eric Sedletzky ), but got a BCD to teach in, since the shop doesn't sell that particular plate. We don't have any plates in the store, but the owners have no problem with me talking about them or ordering them for anyone (another AI uses a BP/W). For them it is more an issue of storage, and yes the contracts they have with some vendors. One of the owners primarily dives a back inflate and I am going to get him in a BP/W at some point!

If those same instructors knew how to properly weight students and themselves they would have a lot less problems with forward pitching on the surface with back inflates and BP/W systems. The old problem of overweighting students still persists in teaching where instructors will knowingly pile on a bunch of weight so the students sink like a stone as soon as they dump air from their BC’s. It requires a lot of extra air just to keep them floating on the surface and the result with an over inflated BP wing or back inflate is the wing want’s to go up thus forcing the person face forward. If they would weight them properly there would be minimal to no air in their wings on the surface and if they combined that with the proper steel tank for our environment there wouldn’t be any problems.
Part of the problem with shops is they love aluminum 80’s for rental fleets and they love jackets with integrated weight systems for ease of set up with students and vertical positioning on the surface while overweighted.

 

[Colliam7]

Part of the problem with shops is they love aluminum 80’s for rental fleets and they love jackets with integrated weight systems for ease of set up with students and vertical positioning on the surface while overweighted.

I have to say that this is a rather insightful analysis of a significant part of the weighting problem. Good comment, Eric!

 

[boulderjohn]

A few months after certification, I bought a back inflate BCD--Zeagle Ranger. That decision had nothing to do with research--I blundered into that purchase. I used it for years before I took the Rescue Diver course and was told by the instructor that my back inflate BCD pushes me toward face down while on the surface. Until she said that, I had no idea that was true. I had just learned how to position my body to be comfortable on the surface while waiting to be picked up. It didn't require any special effort.

Now, if you try that and get comfortable, fill the wing with air, as you might need to if you are very much overweighted. You will have a very different experience.

 

[happy-diver]

When’s the last time you saw someone use one of them?

Hey yeah I very recently used this rig although wearing only shorts
despite the unique look with the crotch strap done up quite firmly

and even with the numbness, I was sure it felt like, I surfaced balls first
but the ABLJ didn't keep them out of the water even though it felt like it

 

[wetb4igetinthewater]

Hey yeah I very recently used this rig although wearing only shorts
despite the unique look with the crotch strap done up quite firmly

View attachment 646902

and even with the numbness, I was sure it felt like, I surfaced balls first
but the ABLJ didn't keep them out of the water even though it felt like it

Do you think this is an appropriate configuration for open water students as compared to both/either jacket style BCDs and BP/Ws?

 

[fisheater]

A few months after certification, I bought a back inflate BCD--Zeagle Ranger. That decision had nothing to do with research--I blundered into that purchase. I used it for years before I took the Rescue Diver course and was told by the instructor that my back inflate BCD pushes me toward face down while on the surface. Until she said that, I had no idea that was true. I had just learned how to position my body to be comfortable on the surface while waiting to be picked up. It didn't require any special effort.

Fortunately, my Rescue Diver instructor was wearing a BP/W, so he never fed me that B.S.

 

[happy-diver]

It worked for me

before the trajectory away from diving by introducing more and more rubbish
unnecessary dive gear turning people into numb robots became unstoppable

so people can actually learn to dive again whilst becoming one with the water
instead of spending too much time involved with ridiculous internet babbling


yeah for as long as you lie to open water students, and treat them like idiots
an idiot you may make

 

[wetb4igetinthewater]

It worked for me

I'm sure it did. But the question is, do you think it is appropriate for open water students (or new divers) as compared to a bp/w or stab jacket?

 

[Colliam7]

I used it for years before I took the Rescue Diver course and was told by the instructor that my back inflate BCD pushes me toward face down while on the surface. Until she said that, I had no idea that was true.

Very true.

I went down the same path - 'blundered' into a Zeagle Ranger. It is actually a very nice unit, very well made, and Zeagle was a company that absolutely stood behind their products. But, that was then.

The challenge with the Ranger, and quite a large number of fabric (aka 'floaty'), weight-integrated BCDs is the placement of the weight, relative to the center of lift. When the diver is horizontal (e.g. underwater) that is not an issue. But, when the diver is vertical, it IS. The integrated weight pockets place the weight 'forward' of the frontal / coronal plane of the vertical (as in, at the surface) diver. The diver's center of lift is behind them, Lift and weight seek vertical alignment (i.e., the center of weight is direvctly below the center of lift), and THAT is what appears to push the diver's face down. It is a matter of physics. It is not a flaw with a back-inflate BCD, although I would venture to suggest that it is a (very real) flaw in the positioning of weight, particularly with a weight-integrated BCD. And, the more (over) weighted the diver, the worse the problem. For some reason, divers at the surface want to float with the water at chest level, rather than at neck level (where it should be). The more air that is added, in an attempt to push the diver 'up' abiove the water, the worse the problem becomes.

Nonetheless, take heart. Solutions are readily available.

1. Proper positioning of weight (e.g. weight pockets on the cam bands of many commercial weight-integrated BCDs represent a genuine attempt to address the design flaw (and that is what it really is) of weight-integrated BCDs. They moive weight fromin front of the coronal plane, to behind the coronal plane.

2. Use of a HP steel cylinder instead of an AL cylinder, which places more weight behind the coronal plane of the diver (yes, the cylinder IS part of a diver's weight system) is an option.

3. Use of a negatively buoyant BCD system, like a SS backplate, which also which places more weight behind the coronal plane of the diver, AND places it immediately adjacent to the diver's center of lift - the thorax - is an option.

I have said, repeatedly, in SB threads that, 'Gear doesn't make the diver, the diver makes the gear do what s/he wants it to do.' The preceding comments in no way change that position. But, when I dive my Aqualung Wave BCD (NOT weight-integrated, which I eschew with considerable enthusiam) I adjust my weight placement to maintain a reasonable balance between my center of lift, and center of weight.