Jacket BCDs, BP/W and bouyancy question

[Diver0001]

Hi,

I'm an inexperienced diver, and budding underwater photographer (certified in 2008, ~70 dives under my belt, 40 in the past year) and I'm finally looking into buying my own kit, and I'm currently wrestling with a few choices. I've only ever dived with (often older, middle-of-the-pack) rental jacket BCDs, but the freedom of a backplate/wing setup, or a rear inflate jacket BCD sounds very appealing. We travel a lot when diving, so weight and transport is a key concern, and we're warm water recreational divers, so the option for full-on multi-tank support is a non-issue, at least for the foreseeable future. I'm looking at several options (xDeep, DiveRite, and ScubaPro's X-tec are all on the shortlist, the latter because it's the only setup my LDS carries, and price for the former two), and I think an aluminum plate and Hogarthian harnass single tank/donut wing should yield a fairly easy to travel with setup.

What I'm mostly curious about is how easy it is to keep station in 'odd' positions with a backplate/wing system; I like flipping upside down (fins up, head down) from time to time, for example to peek under an overhang or rock without stirring up the bottom, and for some macro shots close to the sea floor. Most articles I read extoll the virtues of a backplate/wing for maintaining 'proper' horizontal bouyancy, but what about less conventional positions? Does a jacket-style BCD, with its air distribution around the entire torso, have any advantages in this respect? Does it matter hugely? I usually manage to trim so I barely have any air in the BCD when I'm at depth, so I guess it might not matter too much, but any experiences would be much appreciated...

I own and dive with both a jacket and a BP/W. The jacket for single tanks and the BP/W for doubles and stages. The type of BCD really makes ZERO difference to your buoyancy control provided you have a proper match between the tank(s) and (trim) weights you're using and the BCD. For some applications you really need a BP/W. Jackets -- even ones that claim to be suitable for it -- are bad at carrying doubles and pretty much totally useless for carrying stages. However, if you're a single tank warm water diver then either a jacket or a BP/W will suit your purposes.

Personally for travelling I take the jacket. On diving vacations I normally dive with a single tank and the integrated weight pockets really start to matter after a few days. having most (or all) of your weights on a weightbelt starts to hurt after a while. Normally a BP/W won't have integrated weight pockets. You can buy after market ones but frankly, in this respect, jackets are generally superior because they're made with integrated weights and trim pockets in mind. There are good travel BCD's out there and if you want the best of both worlds, then you might consider a hybrid design instead of a pure BP/W. That said, there's nothing wrong with a BP/W if that's what you want but a pure BP/W with a hogarthian harness and a metal backplate is really only necessary if you think you're going to be diving with doubles at some point. For travelling, a Hogarthian harness might not be the best choice at all. You'll need to get in and out of it in the water and on zodiacs (often times without assistance) and I can assure you that you will soon miss the quick releases. Therefore when you put integrated weight pockets and at least one quick release on a BP/W then what you've basically done is put a square peg into a round hole and turned it into a hybrid style BCD .... so why not look at hybrids that were made for travelling?

Finally, I'll say this. All of the hype about BP/W on the internet is just that... hype. It's mostly at result of people parroting each other. Also, keep in mind that people generally recommend what they own and recommend against things that they don't own. Some of the most negative things you'll hear about gear on the internet come from people who have never even dived with it.... so be warned and keep your mind open. You might be overlooking a better option.

R..

 

[Kairoos]

I use a Zeagle Express tech and I think it's a great BC. It's back inflate, has optional integrated weight pocket, and it's really easy to customize. I've added pockets, a crotch strap, stainless steel d-rings, clips, etc. It's small and light enough to pack for travel as well.

I think it's a good alternative to a BP/W depending on what your goals are.

 

[halocline]

For travelling, a Hogarthian harness might not be the best choice at all. You'll need to get in and out of it in the water and on zodiacs (often times without assistance) and I can assure you that you will soon miss the quick releases.

I'll say this. All of the hype about BP/W on the internet is just that... hype.

R..

I have to disagree with both of these statements. I find the hogarthian harness, properly adjusted, to be easier to get in and out of than any other type of BC, and I've used jackets and BP/W systems with quick releases. Honestly, they're more trouble than they're worth IMO. The simplicity of the webbing harness makes it VERY easy to manage. And I've almost never been in a position to need to get out of my rig in the water despite many years of traveling and diving on very small boats, as well as shore diving.

I agree that most scuba gear arguments, especially about regulators and computers, are largely hype. But the difference in performance between a jacket BC and a hogarthian BP/W system is very substantial. This is one case where the gear choice really does make a difference. Especially important IMO are the rigid plate and simple webbing harness. The plate couples the tank to the diver's body and provides great stability, and the webbing harness tends to 'disappear' in the water, leaving a very uncluttered torso which makes a HUGE difference in comfort IMO.

It is true that good divers can achieve excellent buoyancy and trim control with a jacket BC as well as a BP/W, but that doesn't mean that they are equal in performance. Good musicians can sound great on lousy instruments too...but they certainly notice the difference.

Trim is primarily about weight distribution and tank stability. One good thing about a steel plate is that it puts ballast in a very efficient location, sandwiched between two sources of buoyancy.

Lastly, I would encourage the OP to make scuba gear selections based on how the gear performs in the water, where diving takes place. If you absolutely must make some compromises for travel and/or land use, fine, but remember why you're buying this stuff in the first place, for diving.

 

[Diver0001]

I have to disagree with both of these statements. I find the hogarthian harness, properly adjusted, to be easier to get in and out of than any other type of BC, and I've used jackets and BP/W systems with quick releases. Honestly, they're more trouble than they're worth IMO. The simplicity of the webbing harness makes it VERY easy to manage. And I've almost never been in a position to need to get out of my rig in the water despite many years of traveling and diving on very small boats, as well as shore diving.

I agree that most scuba gear arguments, especially about regulators and computers, are largely hype. But the difference in performance between a jacket BC and a hogarthian BP/W system is very substantial. This is one case where the gear choice really does make a difference. Especially important IMO are the rigid plate and simple webbing harness. The plate couples the tank to the diver's body and provides great stability, and the webbing harness tends to 'disappear' in the water, leaving a very uncluttered torso which makes a HUGE difference in comfort IMO.

It is true that good divers can achieve excellent buoyancy and trim control with a jacket BC as well as a BP/W, but that doesn't mean that they are equal in performance. Good musicians can sound great on lousy instruments too...but they certainly notice the difference.

Trim is primarily about weight distribution and tank stability. One good thing about a steel plate is that it puts ballast in a very efficient location, sandwiched between two sources of buoyancy.

Lastly, I would encourage the OP to make scuba gear selections based on how the gear performs in the water, where diving takes place. If you absolutely must make some compromises for travel and/or land use, fine, but remember why you're buying this stuff in the first place, for diving.

Well... that's where these threads always go. I stand by what I said. Unless you are compensating for poor buoyancy skills with the "basket and blimp", which is where a lot of the enthousiasm comes from, then you can dive equally well in either. I've said it before and I'll say it again; a properly skilled diver could carry the tank in a ruksack and use old milk jugs for buoyancy and make it look easy. All the talk about how much more stable a bp/w is, is just internet hype.

@OP, of course you will have to decide for yourself. As I said in my previous post there is nothing wrong with a BP/W aside from missing weight pockets and at least one quick release. But don't take my word for it. Go ahead and try it. You can always get a quick release and weight pockets fitted after the fact.

R..

 

[Skeptic14]

Jackets are terrible IMO all that way around. They're bulky and don't travel well, they're gimmicky with a lot of unnecessary fabric and padding. they require more weight because they have no inherent buoyancy and actually require some additional weight just to sink themselves, and they flop around a lot because of the way the fabric holds the tank and there's little way to stop that annoying feature.

If an object requires additional weight just to sink itself, that would mean it is inherently buoyant, not sure what you are trying to say regarding the buoyancy and weighting of jackets but you seem to have it backward.

And regarding flopping around and not being able to do anything about it... as a novice diver with very few dives, I have had poor fitting jackets that did exactly what you describe... but after a few times renting gear and finding one that fit me properly that was no longer an issue.

I suspect like with anything, properly fitting gear works better than improperly fitted gear.


And I gotta ask, as a new diver, how does a jacket effect mobility while underwater? Once wearing a properly fitted jacket that is on my torso my arms/legs have more than sufficient mobility for the slow smooth controlled manner in which I thought divers were supposed to employ.

 

[Diver0001]

And I gotta ask, as a new diver, how does a jacket effect mobility while underwater? Once wearing a properly fitted jacket that is on my torso my arms/legs have more than sufficient mobility for the slow smooth controlled manner in which I thought divers were supposed to employ.

Some jackets are just as terrible as Eric described. Most, however, are not. There are still some bulky jackets out there that aren't suitable for travelling but there are also some good low-profile ones out there too. In particular the hybrid jackets fit much like a BP/W but with the extra features I mentioned that a vacation diver might like.

As for jackets "flopping around"...... yeah. You can make any piece of gear suck if you don't get the right size and/or fit it right. This is one example of what I mentioned above about people negatively judging gear that they have never (or seldom) used.

R..

 

[halocline]

If an object requires additional weight just to sink itself, that would mean it is inherently buoyant....

... as a novice diver with very few dives, I have had poor fitting jackets that did exactly what you describe... but after a few times renting gear and finding one that fit me properly that was no longer an issue.

And I gotta ask, as a new diver, how does a jacket effect mobility while underwater?

First, for the buoyancy issue, jacket BCs that have inherent positive buoyancy trap air within the fabric and padding they're made from. This means they need to be offset by wearing more lead, adding to weight on land that must be carried. More importantly, they are depth-sensitive, like a wetsuit, which means that the diver's buoyancy changes more at slight depth changes; especially near the surface. They frequently require more air in the bladder, also resulting in bigger changes in buoyancy as depth varies.

Regarding the mobility, it's a matter of feel. There's a big difference in comfort (of course this is an opinion) between having a cumberbund, extra straps, various buckles and zippers, etc...on my torso and only having simple webbing shoulder and waist straps with a single buckle and a few strategically placed D rings. The air bladder is another issue; on a jacket BC, the air bladder constricts the torso as it's filled; its a little like one of those inflatable casts EMS guys used to use to immobilize injured limbs. (Not as restrictive, of course!) On a BP/W with a good small wing, the wing expands along the sides of the tank and is never in contact with the diver's body.

As a new diver, I suggest that you spend some time with a properly rigged BP/W as well as the jackets you're used to. Then you can decide for yourself if there's a big difference or not. The vast majority of divers, new and experienced, that I have seen switch from a jacket BC (which is what most OW cert classes are taken in) to a rigid plate/webbing harness system, far prefer the latter. I've never met anyone who was taught in a BP/W and then switched to a jacket because they preferred it.

---------- Post added December 30th, 2015 at 08:59 AM ----------

Well... I've said it before and I'll say it again; a properly skilled diver could carry the tank in a ruksack and use old milk jugs for buoyancy and make it look easy.

It is true that good divers can use almost any sort of BC and make it work. But that's hardly a ringing endorsement. Occasionally I still spend a day DM ing for OW classes and from time to time I'll use my old SP jacket BC, which fits me very well BTW. I have no problem maintaining neutral buoyancy and proper trim, but it's much less enjoyable to dive with. Ultimately, diving is about fun.

 

[Skeptic14]

First, for the buoyancy issue, jacket BCs that have inherent positive buoyancy ...

Right, which is the opposite of what Eric said... "have no inherent buoyancy and thus require more weight to sink"...

(of course this is an opinion)

Agreed.

the air bladder constricts the torso as it's filled; its a little like one of those inflatable casts EMS guys used to use to immobilize injured limbs.

Luckily, I don't wear my BC around my entire body so my legs and arms are free to bend. It is a feel/personal preference thing, and selling it as jackets are restrictive seems to be a stretch.

Outside of the BC being on so tight that when inflated it squeezes the person to the point that their diaphragm is restricted and breathing becomes impaired I just don't see how they are restrictive. I cannot see it being anything more than poorly fitted gear working poorly.

Ultimately, diving is about fun.

I agree, and I don't see how a properly fitted jacket inhibits fun.

---------- Post added December 30th, 2015 at 09:33 AM ----------

As for jackets "flopping around"...... yeah. You can make any piece of gear suck if you don't get the right size and/or fit it right. This is one example of what I mentioned above about people negatively judging gear that they have never (or seldom) used.

R..

To me and my limited experience this seems paramount regarding gear. Is it the right size, fit, and have the feel that you are comfortable with?

Whether that means, jacket, bp/w, or rucksack with milk jugs

 

[Eric Sedletzky]

If an object requires additional weight just to sink itself, that would mean it is inherently buoyant, not sure what you are trying to say regarding the buoyancy and weighting of jackets but you seem to have it backward.

And regarding flopping around and not being able to do anything about it... as a novice diver with very few dives, I have had poor fitting jackets that did exactly what you describe... but after a few times renting gear and finding one that fit me properly that was no longer an issue.

I suspect like with anything, properly fitting gear works better than improperly fitted gear.


And I gotta ask, as a new diver, how does a jacket effect mobility while underwater? Once wearing a properly fitted jacket that is on my torso my arms/legs have more than sufficient mobility for the slow smooth controlled manner in which I thought divers were supposed to employ.

That's what I meant, they have too much inherent buoyancy. Thanks for the correction.

 

[dmaziuk]

And I gotta ask, as a new diver, how does a jacket effect mobility while underwater? Once wearing a properly fitted jacket that is on my torso my arms/legs have more than sufficient mobility for the slow smooth controlled manner in which I thought divers were supposed to employ.

It depends: if you're deep/cold enough to have to start inflating it underwater, there may be a bit of a squeeze. If it's loose enough to allow for that, then there's some flopping around to live with until you get to your target depth. But generally speaking: it shouldn't have any significant effect on mobility. You'll have a little bit more drag and wear a little bit more lead and none of that should make any difference to a leisurely drift in a gentle current.