BP Wings vs BCD explanation

[ScottyK]

MikeFerrara once bubbled...


The dramatic diference comes in when you compare the whole equipment configuration.

I had never heard of DIR or the Hogarthian configuration before I found this board. I've been doing a lot of research on it and, on paper, it looked very well thought out.

I always considered myself a "streamlined" diver. I use a back inflate BC, and purposely picked my model because it's not loaded with giant pockets and other extras. All my gear is neatly clipped off and as flat against my body as I can manage.

I finally had the pleasure of seeing the whole Hogarthian setup up close when a friend I made here on Scuba Board, Docmartin, came out and joined us for a dive a couple of weeks ago. Even reading the DIR-F book didn't prepare me for the dramatic difference the gear makes. I suddenly didn't feel so streamlined anymore. In fact, I felt more like the Michelin Tire Man standing next to him.

Needless to say, we're going to be using the down time this winter to re-configure our gear. I'm not selling any of my old stuff until I get a chance to dive the new setup enough for a fair comparison to be made. However, I have a funny feeling that I'll be posting some well cared for gear on EBAY in the near future.

 

[SeaJay]

paulwlee once bubbled...


Actually, when I'm talking about 30lbs I'm talking about my total weight requirement for using a single AL80, including weight belt, backplate and everything else. Right now it's the weight belt and SS backplate, which means I am wearing 24lbs on the belt.

Ah. I didn't realize you were already at that point. I remember you talking about it...

With the E7 100, I will need 5.3lbs less, and I can probably manage to drop 6lbs, so I'll go to a 18lb belt. If I do get a canister light, I'll be going for a Proteus 3 or 6, with -2 or -3lb buoyancy, and the belt will drop to 15 or 16lbs.

That would be pretty sweet. What about if you took the above configuration and used a weighted STA? And did you take into account the extra weight of the Jets like you pointed out in your post above?

As for the balance point, if I am not able to get balanced comfortably with the E7, then I'll probably look at ACB's or trim pockets. I think if I am able to move my weightbelt up a little it would be fine, but I'm already at the limit because the belt is sitting just below my waist strap.

...Sounds like you've got it under control. I didn't mean to imply anything else.

 

[MikeFerrara]

ew1usnr once bubbled...


It's true that the front of my stab jacket is not lined with rows of D-rings.

Actually some bc's are. That isn't at all what we want. I've seen bc's with 18 or more d-rings and not a single one was in a usable location.

That's why I have two D-rings attached with a big hose-clamp to either side of the base of my tank. I reach around and behind to clip off stuff. That is more out of the way and less of a danglie than if something were clipped to D-rings on front.

that's another place where I don't want it. I want my tanks as smooth and snag free as possible. I don't clip things off in front. The only thing that goes in front is my back up lights and they lay flat along the shoulder straps completely secure, not dangling and easy to deply. The only other thing that gets clipped is my SPG (to my left hip) and maybe a reel. I wouldn't want my SPG or

As for the gauge or console, all you need is one place to clip it to. That's easy enough to find. I put a D-ring on the waist strap. You can even just feed the gauge and hose under the shoulder opening to keep it in front of you. (I say shoulder opening rather than shoulder strap, because the stab jacket does't have a harness or shoulder straps. That's another point of the stab jacket, keep it simple. )

Lots of bc's especially weight integrated ones or those with a cunberbunn don't have a place on the hip for a d-ring. the rings they put in front don't count and I cut those off and toss em.

I see divers with their HP hose stuffed through the shoulder opening. The hose is too long and the consol dangle way out in front. We use a hose just long enough to get the SPG to the hip. The hose lays flat against my body and nothing sticks out anyplace. The only thing I need in front of me is my bottom timer and that's on my right wrist so I can see it without moving a muscle or changing position in any way.

The jacket itself may be seem simple but when you start hooking up everything else and trying to get it to work it's all of a sudden not so simple. The pieces just don't fit together.

 

[Wyno]

-hh once bubbled...


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

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.

-hh [/B]

I only do recreational diving and only had about 15 hours on my BC before I had a falure on my plastic connctor. It did not break but it just doesn't have the loud click anymore and somtimes comes disconnected durring the dive. It will need to be replaced. But I now have a BP/Wing setup so that one will probally go up for sell after I replace the connector.

Dan

 

[-hh]

SeaJay once bubbled...

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?

Knowing how many failures occurred is not useful without also knowing the context. For example, the USA's highway fatality rate of 40,000+/year sounds dire, but because its consumption-based, it can also be expressed in the context of 1.28 fatalities per 100 million miles driven. Since it will take the average driver over 6,000 years to drive 100 million miles, his risk is pretty low: it can also be expressed as a 0.0192% risk of fatality per year (based on 15K miles/year)...same numbers.

I'll tell you what... Why don't we take a poll...

A good quality poll is quite difficult. I'm not saying it couldn't be done, but betwen issues of self-selected samples, leading wording, user demographics and the need to also collect usage context(*), its going to take some work.


(* - for example, you need to know more than how many rental BC's were in the diveshop: you also at least need to know for how many dive-days they were used, because you don't want to create a false "credit" from equipment that was never used).

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

The first thing needed is to understand the exact question being asked. I view the QD reliability question to be trying to examine the probability of a failure "during" a dive, from a nominal useage and nominally dive-attributable cause.

For example, if a diver is attacked by a Great White Shark, should it or shouldn't it? Similarly, what if the gear gets run over with Dad's snowblower while in winter storage? Or mice chew through it? There will always be interpretational grey areas.

One grey area that does need to be seriously considered here are sources of accidental breakages while the gear was in transport to/from a dive. This includes stuff such as from a falling tank, being slammed in a trunk/tailgate, etc. This can be justified both ways, for while these risks are indeed part of the normal lifecyle environment, the majority of these risk are avoidable through reasonable "due care", which is mostly just common sense.


-hh

 

[SimonN]

jplacson once bubbled...
Well, afaik, they are the group that gives DIR-F classes and GUE classes. They profess DIR methods of diving, and most of the diving community points their way if you wanna go the DIR path.

Interesting, Martin Lorenzo (one of the two GUE instructors in Asia and the only one in the Philipines) was my DIR-F instructor and he never mentioned being overweighted was a good thing under any circumstance.

 

[jplacson]

Simon, I've heard of Martin... Is he still the only GUE instructor in the Phil? Anyway, these guys give DIR-F classes as well, so I really don't know.

Maybe they were just afraid of me being underweighted... I really don't know what there reasons were. I was asking for the differences between the AL and SS plate and which one should I use..blah, blah, blah...

They recommended the SS for 'safety' or something ... even a few other tech divers I asked said to get the SS, even if I only used 4# in a stab jacket...something about it being easier to hold a 15' stop in choppy waters... which kinda makes sense I guess if you're heavier, it should be easier to be stable? I don't know.

Anyway, thanks to Seajay's persistence on proper weighting... I decided to borrow an AL plate and bring along a belt with 2-pounders clipped on... towards the end of my dive, I asked my instructor to help me out as I handed him my weights one by one until I was neutral.

Well, I'm down to just a 2# trim weight and the AL plate. I'm very happy with my rig! :lol:

 

[Matthew]

SeaJay once bubbled...


Not exactly.

The point that I made was that bp/wings have different trim characteristics. There is no skill which can surmount a trim problem unless you fin and work to remain properly situated. You simply either fin (or use your hands) to get horizontal, or you address it from an equipment standpoint and change your trim through the proper placement of weight. That's it... There is no "skill" which you can develop to suddenly make your body balanced in the water column.

That's not it. Let me point out that problems in maintaining UW position/balance is not always a trim problem. It rarely is, especially in a country like the Philippines where almost all diving is done with thin wetsuits, single aluminum 80 tanks and very little weight. It is usually just a newbie problem (usually due to wearing too much weight and consequently, having too much air in the bc thus pushing the diver into a vertical position) which never fails to resolve after gaining a few more dives, especially with instructor intervention. It is the resolution of problems like this that result to significant improvements in air consumption. So when I see someone struggling to maintain position, using the hands to stay horizontal, etc. should I immediately decorate him with additional weights? Should I advise him to shift to a bp/wing setup?

This trim issue is fixable using trim "band aids" like placing ankle weights on your tank valves... In some cases where not much trim weight is necessary, the pockets on some of today's better "regular BC's" are enough to get fairly good trim out of them. My point was, "why do that, when it's built into a bp/wing?"

I don't believe its even an issue since here, divers using trim weights seem to be the exception. I have never seen ankle weights on tank valves. Some, including myself, bother with the placement of weights on the belt and nothing else. But I assure you that we can effortlessly maintain a horizontal position or any position we desire. I just want to dispel the impression that trim issues are inevitable when using a BC. I also prefer that my gear not dictate my stance in the water, and the bc gives me the freedom.

How do you know? Have you ever tried a bp/wing?

Yes. I really liked the way my front and sides were freed of stuff, and the way I didnt feel squeezed when inflating. And as jplacson says, it really looks cool. I found it comfortable, although I felt awkward when I tried to do some of the things we like to do like hovering at an angle, hanging upside down, etc. Maybe it just takes some getting used to. I'd also prefer to be in my bc when waiting to get on a boat in a very rough surface, which situation I often find myself in. I cannot say for sure because a lot of factors have to be considered, but I feel my air consumption, had I done the same dives with my bc, would roughly be the same because I noticed little difference in my comfort level.

It is a fact that a bp/wing setup is much more versatile and configurable. However, if one is limited to certain types of diving, a bc would work as well, or even better. Here you can get a decent bc for 8,000 pesos (about $145) and the Halcyon bp/pioneer 27 for 28,000 pesos (about $509). So, don't you think it would be wiser to consider the type of diving you intend to do before choosing instead of just going for the setup which is proclaimed the best by some people, even if its advantages, while real, are not likely to be realized in the kind of diving you do?

I hate having to repeat all these things which have been said many times already, but you say you can't see why one would choose a bc over a bp/wing. Where were you looking?

I do? Please read the article I wrote about the 30+ BC's I tested last year and how they stacked up against one another...

Where?

 

[jplacson]

Matthew, are you saying that you have trouble hovering in weird positions using a BP/wing? Hmmm... you may be weighted properly, but your weight distribution may be a bit off.

I don't think my trim weighting is DIR, but it does keep me balanced in most positions. DIR trimming positions the diver horizontally which is optimum for cave & wreck where you wouldn't want to accidentally float vertically and smash your head on the cave/wreck ceiling. :O

My trimming isn't as stable horizontally (ie: if I roll sideways, my body will stay sideways till I roll back, if I tilt up/downwards, I hold that position until I start finning again and regain a horizontal position) it's not DIR, and not for wrecks.

I placed my trim weighting (2#) on my upper tank strap, away from the bladder... kind of a counter-weight. This makes my back swing back easier when I take a vertical (either up or downward) position, since it's only 2# it doesn't cause me to roll uncontrollably in any direction.

The disadvantage of my weighting is really in tight areas since I cannot regain a perfectly horizontal position without finning a bit (1 kick will do...but in a close overhead environment, this is unacceptable)

But it works for me since I'm only certified for OW dives. I even tried hovering upside down... Again, I still need a kick to move forward and regain horizontal positioning.

I tried putting my trim weights closer to the wing, and although I can still hover in diff positions, it does have a tendency to float you face-down. No biggie... I'm still experimenting with what works for me.

P8,000 for a decent BC?!?!? Where??!?! Hmmm... maybe I should've gotten that over my Halcyon!!! :lol: hahahaha... just kidding!

BTW, don't forget, your fins make a HUGE difference in trim weighting, Jet's WILL sway you vertical since they are negative... so a BP/wing with an SS plate and trims close to your body will counter-act that and keep you horizontal... but you have to take into consideration you fins as well when trimming.

 

[SeaJay]

Matthew once bubbled...

Where (is the article you wrote about BC's and trim)?

http://205.240.35.88/homebc.html