BP Wings vs BCD explanation

[SeaJay]

Congratulations on completing the course.

Who was your instructor? How 'bout a report?

What'd they say about needing 30 pounds of weight?

 

[asemili]

What does BP stand for?

 

[-hh]

I'm of the opinion that any plastic connector failure is significant, since you can use skills to nullify their use.

IMO, any failure is potentially significant. And while some objective risks can be displaced, others can be accepted as is: no additional overmatch (overdesign) is functionally required.

-hh, you stated a claim: That plastic connectors breaking aren't statistically significant, yet you've only gathered information from one biased source - yourself. I'm simply saying that if you want to prove your point, you first need to gather many more samples from unbiased sources.

If a 1000 hour MTBF is good enough, no additional sampling is necessary.

But since you apparetly disagree, it must be because you don't cosinder the MTBF to be good enough. That's fine: needs vary. But please humor me with expressing just what MTBF value you consider to be necessary for your diving.

FWIW, I had no preconceived notions about QD's reliabilty versus anything else one, five, ten or twenty years ago. That's where this data stems from. It wasn't until ~2 months ago when this "QD=bad" claim came up that I even thought about looking at the data.

IMO, I consider a 1000 hour MTBF to be good enough within my context of recreational diving.

For technical overhead diving, I might want to bump it up a little, but then again, I'm also of the opinion that a diver should have a couple of hundred hours of bottom time before even considering that type of diving.


-hh

 

[boomx5]

asemili once bubbled...
What does BP stand for?

Backplate

 

[asemili]

Ahah thank you that helps. I was starting to think it stood for "Blood Pressure" with the way this post is going

 

[ew1usnr]

I still think that the air shift is more dramatic when you roll to the side with wings, than it is if you are wearing a Scubapro stab jacket. The jacket holds the air closer to the body.

 

[jplacson]

Which is why I like the "O" design of the Pioneer wings over the traditional "U" shaped ones. I think DiveRite's wings are O-shaped as well, as is the upcoming OMS wing.

 

[SeaJay]

-hh once bubbled...


IMO, any failure is potentially significant.

I agree completely.

If a 1000 hour MTBF is good enough, no additional sampling is necessary.

But since you apparetly disagree, it must be because you don't cosinder the MTBF to be good enough. That's fine: needs vary. But please humor me with expressing just what MTBF value you consider to be necessary for your diving.

No, I'm not saying that a 1000 hour MTBF isn't good enough... I'm saying that you have one sample of that situation.

I believe that if you took a poll, for example, and asked a variety of divers worldwide if they've ever seen a crushed or broken plastic QD, I think you'd find a statistically significant positive response. Even if it's only 25% of the divers, that's more than 60 incidents of a failed QD in a set of 250 sample data. I think that we could both agree that that would be statistically significant.

...And what would be a more accurate statistic - to quote one individual plastic QD which hasn't broken in over 1000 hours of use, or an incident of 250 random samples?

I'll tell you what... Why don't we take a poll... Grab, say, 300 divers right off their board and ask them two questions: 1. How many BC's with plastic connectors do you have (if you're a dive shop owner/worker, include rental gear but not unsold new equipment) and 2. Count the broken connectors that you currently have, and add that to the number of broken connectors you've replaced in the past year. That should give us a rather statistically accurate, unbiased view on what sort of failure rate these things have.

Then we can debate whether or not the numbers are statistically significant.

Heck, while we're at it, I think we should also do a poll on webbing replacement, and gather some actual streamlining data like you were talking about.

Heck, we could end up the "Bill Nye Science Guys" of Scubaboard...

 

[ScoobieDooo]

Problem with that SeaJay is that this message board is slanted with tech divers who prefer BP's & wings and not your standard, 'off the shelf' recreational diver who reads Rodale's Scuba Diving magazine which do not partake in 'technical' diving and finds that jacket BC's fulfill all their needs.

One has to consider WHY someone IS using a BP & wing - is it because it's inherently better or because their style of diving requires it - due to mounting stage/deco bottles, diving twins, needing wings with tons of lift, etc.

For ANY poll to be accurate one must consider what sector of the masses that is being surveyed. In this case, it'd be mostly tech divers...and that’s not a impartial poll.

 

[paulwlee]

SeaJay once bubbled...
Congratulations on completing the course.

Who was your instructor? How 'bout a report?

What'd they say about needing 30 pounds of weight?

Instructor was Joe Talavera, who's a local guy. He's a Cave2 and Tech1 diver, and going for his Tech 2 this week.

I think there were enough DIRF reports around here, so I'll refrain from writing one. (Actually, I'm too lazy to do it. )

As for the weight, you may have a hard time believing it, (you seem to question me on this again and again) but we need a lot of insulation to dive the 45~55 degree water around here. I'm close to neutral with ~500psi in my tank at ~15ft, with a snugly squeezed drysuit. I used to dive with 16lbs in my 5mm farmer johns until I moved to this area, so I know it's a lot of weight, and I would love to get rid of some of it if I can. Doesn't seem like it's going to happen any time soon. If anything, I'll probably need more if I move to a thicker Thinsulate undergarment for deco diving. At least my new PST E7 100 steel tank will let me drop 5lbs from the belt.