From jacket BC to back plate and wing?

[burna]

It sounds like your one BP/W is easier for you to dive than your one vest BC, so now you claim on the internet that BP/W's are easier to dive than vest BC's?

Well, I much prefer my BP/W to my rear inflate BC and really, when it comes down to it, that's all that matters.

 

[InTheDrink]

I have owned a ScubaPro (adjustable shoulder strap vest? - circa '91) and numerous SeaQuest ADV's, as well as a SeaQuest Balance. I have worked students/customers with shop gear that included Oceanic vests (circa '02), ScubaPro Classic (circa '04), multiple SeaQuest vest operators and Mares vests which have just recently been discontinued; only a few Oceanics and the "new" ScubaPro's were integrated weights.

How many different vest BC's have you used and how many different BP/W's have you used?

Not sure what you'd be confused about. I've dived a lot of jacket BCs, mainly rental but for 20-30 per rent. I've dived my Mares dragon for a couple of years. So my experience of specific models is limited but my experience of the principle is reasonable.

It sounds like your one BP/W is easier for you to dive than your one vest BC, so now you claim on the internet that BP/W's are easier to dive than vest BC's?

I didn't say easier, I said easier to dive well in. I stand by that remark for all of the reasons already mentioned in this thread. I stand by the fact that a BP/W or back inflate promotes better trim than a jacket BC. Clearly good trim is achievable with both styles. However the BP/W design inherently promotes a more horizontal position in the water by virtue of where the bladder gas is in relation to the diver not to mention the more even distribution of weight (e.g. SS BP).

I do not feel that my vest BC's "ride up" but perhaps that is because I am the rare HWP guy with a waste.

Well that's good. It was one of my main complaints with jacket style. Perhaps having your shape does help with this. I'm not in bad shape myself but I still found it rode up and frequently had to pull it down again. I'm fairly sure I'm not alone in that experience.

I am not making claims; I am telling you what I have experienced and seen with specific gear. I thought the current discussion was about streamlining. I also regularly state that from a physics perspective, a well designed vest has to release air easier than a well designed BI or BP/W, due to the position of the bladder being lower/closer to the body when horizontal.

Other than being streamlined and releasing air easily, what other criteria causes a Buoyancy compensator to be the best to dive well in?

Well, I think the thread had a broader remit than simply streamlining but perhaps I read it wrong.

Not sure what you mean when you say 'a well designed vest has to release air eaasier that a well designed BI or BP/W'. What's the relevance to releasing air and being streamlined? Am I missing something?

I would say that from a physics perspective, a back inflate or BP/W together with crotch stap has to keep the bladder and gas in it in a more uniform place across the diver than a jaket BC, and thus promote better trim which is essentially better streamling.

Clearly YMMV.

Cheers,
J

 

[Sas]

Well, I much prefer my BP/W to my rear inflate BC and really, when it comes down to it, that's all that matters.

Ahh burna, I love reading each of your comments about how much you like your BP/W

I think you were the last buddy converted??

 

[diverrex]

One of the big differences I note with my BP/W is it holds the tank exactly in place. With my BC sometimes the tank would move a little to the side and mid dive I would sorta jerk my back some to throw the tank back to the middle.

 

[halocline]

Scuba tanks, being cylinders, present a very small point of contact against your back. The beauty of the metal (or rigid plastic) plate is that it spreads the point of contact between your back and the cylinder over a nice large flat area. This is what makes it so much more stable and comfortable with a tank on your back. Regardless of what type of BC or harness you use for diving, you need to somehow mount a metal cylinder against the flat surface your back. A flat plate does this most effectively. The logic of this is very difficult to successfully argue against.

I strongly prefer the simple webbing harness to padded harnesses; I just enjoy diving with much less clutter around my torso. That's a personal opinion, though.

To the OP, if you go over to the BC forum and search for threads about the relative virtues of BP/W systems vs. jacket BCs, you'll have enough reading for several months, and by the time you're finished with all those threads, you can re-do the search and find a thousand new threads......

I'm just as guilty as everyone else posting on the zillionith thread on this topic. We just can't seem to resist.

 

[MauiScubaSteve]

Okay, I have issues with this. When you are in a horizontal position in the water, any air you have in your BC will go to the highest point, which is your back. Assuming you are properly weighted, and therefore have very little gas in the BC to begin with, what is there about the fact that the jacket bladder extends down around your body that is going to help you vent? If you have enough gas to have any down there, you've got too much air in the BC.

OK, when horizontal any air in a Vest bladder is lower than a similar amount of air in the bladder of either BI or BP/W BC's. Getting the deflator hose above a lower bladder of air is physically easier compared to a bladder not as low; one does not have to lift the deflate hose up as much to get it above the bladder.

OK, when slightly head down the kidney dump of a Vest BC is right next to the body, where as the kidney dump of a BI BC is "winged-out" away from the body, meaning the diver has to reach farther to perform the dump. Is the "bottom" dump of a BP/W as close to reach as the kidney dump on a well designed Vest BC?

 

[MauiScubaSteve]

How many BP/Ws have you tried Halemano? There's nothing wrong with disliking BP/Ws like you do, but there is a lot wrong with asserting incorrect things about them such as you seem to like to do.

I do not dive doubles or dry, so I have never had a reason to use a BP/W.

I am only asserting that; from a basic physics standpoint I will need scientific data to not believe a well designed Vest BC is more streamlined than well designed BI and BP/W BC's and from a basic physics standpoint I will need scientific data to not believe air release from a well designed Vest BC is easier than from well designed BI or BP/W BC's.

I do not dislike BP/W's, I dislike the use of red herring arguments. If someone is going to dive doubles they should seriously consider a BP/W. If someone is going to dive dry they should probably consider BP/W. If someone is just a typical, average diver the reasons for considering a BP/W are not so pressing, IMHO.

 

[MauiScubaSteve]

Well, I think the thread had a broader remit than simply streamlining but perhaps I read it wrong.

You took issue with the following post by me, which made streamlining the topic of the moment.

My Instructor is a hard core Florida cave diver. He gave me the following pros:

4. More streamlined

Did your Instructor give you anything but his anecdotal opinion on this?

I mean has anyone got a link to some data that shows which rig is most streamlined.

 

[MauiScubaSteve]

Not sure what you'd be confused about. I've dived a lot of jacket BCs, mainly rental but for 20-30 per rent. I've dived my Mares dragon for a couple of years. So my experience of specific models is limited but my experience of the principle is reasonable.

I was not confused, I was unimpressed by your decision to generalize on all BC's based on you not having used all BC's;

A BP/W is easier to dive well in. Jackets tend to ride up

 

[PfcAJ]

I've yet to dive a jacket that doesn't ride up.