Switching from Jacket bcd to Backplate/Wing??

[DeepSeaDan]

Using your drysuit as primary buoyancy creates the problem of bubble location even worse than oversized wings do... If you tilt up or down while diving, the bubble runs from your shoulders to your feet and throws the whole concept of being in control out the window... ESPECIALLY if you are using steel 130s and needing to compensate for 30 pounds of buoyancy swing! That's a 30-pound bubble traveling from your shoulders to your feet and back again... Why do that when you have a wing that keeps the center of buoyancy closer to your center of gravity?

One of the keys to diving dry is to avoid using your drysuit as inflation, and minimize the amount of gas that you have in the suit... "Just enough to keep the squeeze off," as they say. What drysuit course recommends the practice of using your drysuit as buoyancy control?

...Not that it couldn't be used in an emergency - assuming that the emergency wasn't an OOA - but why do that when you've got a BC?

For that matter, why use a BC if you're using the drysuit for buoyancy?

I have a problem with disc-deterioration in the lumbar spine, & the weight of the 130's gets very fatiguing, thus I "lift" the weight off my lower back with suit inflation, and a nice, comfortable dive.

I use a bcd just in case my dry-bag's air-integrity fails, the suit floods, and my 130's make me a human anchor, sans bcd.

DSD

 

[Deep South Divers]

3. Deep South Diver: Try not to be condescending. Try to stay calm.

I beg your pardon? I don't know who you think you are to tell me what to say or how to act or how I should come across, but your condescending attitude, telling me not to be condescending is... Condescending. If I met you in person I'd probably knock your teeth out for saying something like that to me.

5. I like my kit. It works well for me.

Cool. Knock yourself out then. I couldn't care less how you dive. I simply wanted to offer a voice of reason to the average reader here just in case they thought that your ideas were good ones.

Funny... Three months before I recovered the body of my buddy who practiced some of the same numbskull ideas that you do, he told me the same thing that you are now. "Calm down and try not to be condescending," as if *I* was the problem. Whatever. Feel free to dive how you want... But this time I'm not the one that's gonna do the body recovery.

My advice to you: Reread the Basic Open Water manual of whatever agency you're certified with... And pay attention this time.

 

[Kern]

Try a Kit Kat.

 

[DeepSeaDan]

SeaJay,

If you don't think "DeepSeaDan, open your PADI OW manual and read the first few pages on how to weight yourself properly.", is condescending, you need to look up the definition of the word.

You're seem like a pretty knowledgeable guy, you just need to learn to couch your advice with some tact, humour, & a wee dram of respect. I also find it better to address a post's points directly, rather than launching into a disertation.

Lastly, I've been around this game for 36 years now, so I must be doing a few things right.

DSD

 

[Deep South Divers]

The guy I pulled out of the water said exactly the same thing to me. Feel free to search for it... I have made references to his case several times over the past decade or so that I've been here, and every time I tell the story, I include the part where he says that somehow, I am his problem, and HE has no problem, and that he'd been doing it a long time and therefore everyone else is wrong.

I'm not offering an opinion of what he said... Just giving you the facts. You are doing the same thing, defending them the same way, and are telling me the same things that he did. That's a fact, not an opinion. Draw your own conclusion.

I'm flattered that you would call me "knowlegable," but I'm past the "use tact and humor and respect" learning stage in my life. I did that when I was a teenager and young adult. Now I tell people the way it is when they need to be told that they are diving stupid and placing their lives (and others) at risk. Consider it a sign of caring that I'd feel strongly enough about it to try to convince someone to stop putting themselves and others at risk. Sure, humor and tact (respect is earned, not given) go a long way, but the truth goes even further. If you can't find any agency supporting your dive methodologies, you might want to honestly reconsider.

But whatever... As I've said, I really don't care how you dive, and since you're not in my area, I won't be doing the body recovery anyway. But don't try to tell me what to do, how to do it, or what to say or how to say it. I live in a free country, Dan, and if you've got a problem with my attitude, then find the ignore button and use it.

I certainly will.

 

[Aqua-Andy]

What? To quote "Teller" from http://www.scubaboard.com/forums/basic-scuba-discussions/324515-drysuit-buoyancy-5.html : "SSI says to only add enough air in your dry suit to avoid the squeeze and then add air to your BCD as needed. I have tried both ways and I find it easier to control the air in my BCD rather than in my dry suit."

I can't imagine any agency recommending the use of a drysuit's inflator and dump as buoyancy control, for the reasons I've mentioned... That it places the center of buoyancy and center of gravity far apart, which creates a situation whereby trim and attitude is impossible to control. Can you cite a specific reference?

This is how the paragraph reads, I had to dig my book out to find it. My book is four years old so they may have changed there wording, I will check a new book at the store next week.

Add just enough air to keep from being squeezed. There should be no large pocket of air in your suit if you are weighted properly.
During your dive, keep just enough air in your dry suit to maintain neutral buoyancy so you can hover in a horizontal position, neither head up or head down. Use your dry suit to adjust your buoyancy under water. Do not add air to both BC and your dry suit. It is too difficult to adjust and control both volumes of air at the same time. The only time you should use your BC under water is when your suit floods, or is damaged and will not hold air.

In a single 80 it works good for me, but not in doubles as I said before.

 

[Deep South Divers]

Hm.

The text is worded a bit oddly... First, they say exactly what you and I and everyone else in the poll on the link I provided is saying... To inflate the drysuit just enough to take the squeeze off... Then it goes on in the same paragraph to say to use your drysuit as your buoyancy control. I don't see how you could do both simultaneously unless you do exactly what you're precluding... Use that to compensate for only a very small buoyancy swing.

A pair of steel 130's swing 20 pounds from full to empty. A single AL80 only swings six. Add to that compression at depth of whatever it takes to keep the squeeze off, and yes, you would have a rather large bubble - as we've described before, maybe 20 or 30 pounds of lift worth - moving around in the drysuit. One poster even remarked that it's enough to use as a cushion against his backplate and heavy tanks. Certainly a bubble like this couldn't be considered "...no large pocket of air in your suit..." by SSI standards.

Perhaps they've reworded it recently. I look forward to seeing what they have changed about it in the latest rendition of the SSI OW manual.

More discussion on this SSI issue of using a drysuit as a BCD can be found here: dry suit training padi vs ssi [Archive] - ScubaBoard Notice that both PADI and the drysuit manufacturers advise against this practice and teach to inflate the drysuit only enough to take the squeeze off... And then use a BCD (of whatever kind, whether it be back inflate, vest, bp/wing, etc.) to compensate for buoyancy.

 

[Zesty]

Thanks for the thoughtful information!

........ That said, a backplate and wing is superior in every way to any of these BCs. It's more streamlined, more rugged, more customizable, and more simple. Backplates and wings can also handle doubles, stages, and even rebreathers, which none of the above is equipped for.

OK - more pumped up now!!!

The Highland cam bands are really nice. I haven't yet decided if I like them better or their similar-functioning Scubapro or Deep Outdoors (which are actually a generic rebadged) cam band... The point is that the cam band comes completely apart. This idea is unique in the industry and a huge advantage on a rocking boat or to "quick change" tanks between dives.

Agree - most of my diving is from a boat (thats just life in the great lakes) and the ease of removal has been very evident several times!

Let us know how the Dive Rite harness works out for you. I have a feeling that you'll find what many of us have found... That because of the fact that the shoulder straps are close together at the top and further apart at the bottom of the plate, the easiest way to get out of a bp/wing is to lift the rig off your shoulders before trying to don or doff. Since the shoulder straps - unlike most BCs - are not parallel (and are designed to be much more loose than most BCs), quick releases become unnecessary. Which is great - one less thing to go wrong.

Alternatively, if you have a medical condition that prevents normal doffing or donning, then... Well, just let us know how it works out for you. If you HAVE to use one, a stainless weight belt buckle like Halcyon, Scubapro, and Dive Rite make is a safer, more secure option that won't become brittle in the sun or break when someone steps on it on the boat. This method works with any harness, Hogarthian, DIR, Deluxe, or whatever.

Interesting point WRT the triangular set up of the harness straps - I will let you know how the egress / ingress is. If a stainless buckle is used - when securing, do you feed the strap down or up? My initial thought is that you feed it down so that when the buckle is locked, the release is pointing down .......

For what it's worth, I would recommend that you try the stainless plate first and see how it balances you out. .............

The problem here is that I am being offered a one-time, very competitive price - the more I buy, the better the discount ........... I guess one can always sell stuff if need be ...........

 

[Deep South Divers]

Thats cool... If its to your advantage, then do it. I can tell you, though, that in my shop (commercial divers, not a retail shop), all of the stainless plates are in use (rigged) and all of the aluminum plates are hanging on the wall, unused.

That said, all of us are diving aluminum 80's and almost always in salt water. Most of us are diving wet.

We prefer the aluminum tanks to steels for a few reasons:

1. Both tanks corrode in the constant presence of seawater. When aluminum corrodes, it makes aluminum oxide, which is dark gray and harder than aluminum. In other words, as an aluminum tank corrodes, it corrodes less. The aluminum oxide can be considered a protective coating which slows the corrosion process. When a steel tank corrodes, it softens and accelerates the corrosion process, not to mention gets rust everywhere.

2. Aluminum tanks are neutral when half empty. This means that plus or minus a couple of pounds, the tanks are generally neutral in use. This enables us to weight our rigs such that the center of gravity is close to the center of buoyancy, reducing a rig's tendency to tilt the diver in a way that he didn't want to be tilted. As such, a diver is able to choose any position he wants to get a job done... And stay there. If we used heavy steel tanks, it would move our center of gravity higher away from our backs, and there would be a tendency for the rig to "turtle" the diver if, for example, he were to attempt to work while on his side.

3. Aluminum tanks are widely in use. That means that if we travel and use another operator's tanks, we are likely to be weighted correctly without any modification. If we used steel tanks and went to use someone else's aluminums, we'd have to alter our rig - add weight - to compensate.

4. Aluminum tanks are much less expensive. We have some 30 tanks in our inventory, and have spent something like $200 for each tank. Total investment is around $6k. If we were diving steel tanks, we'd likely have close to twice that invested. There is no cheaper way that I know of to get gas underwater than by using the ubiquitous aluminum 80.

5. Aluminum tanks, because of their "neutral when half full" characteristics, can be simply and easily and quickly rigged as stage bottles. The same can not be said for steel tanks. Thus... If a diver wants more gas, it's a very simple process to rig him with multiple tanks... Singles, doubles, stages, multi-stage or even drop tanks... Whatever he needs. Having all aluminum tanks in our inventory gives us the maximum flexibility that we need.

If we were diving with steel tanks, we might be more apt to use our aluminum plates. After all, trimmed correctly and compensating for buoyant lung tissue, a diver typically wants about six pounds over their lungs for a close CofG/CofB orientation. If we were using steel tanks with more inherent negativity than an aluminum tank, we'd probably opt for the less negative aluminum plate to compensate for the heavier steel tank... So that we're puting six pounds over the lungs, not 12.

...So the real question for you is... Are you diving with steel tanks or aluminum? If you're diving aluminum tanks for the reasons I mention above (and "because everyone else is and they're widely available" is a surprisingly valid reason so that you're flexible without having to reweight), then I would recommend sticking with the stainless plate. The only time I see people preferring an aluminum plate is when they're diving heavy steel tanks, and then only to fix a trim issue.

Rarely I see aluminum plates in freshwater on a diver who ia not wearing a wetsuit or in a travel rig where the reduced couple of pounds is advantageous to them... But they pay the price of having to search for lead and weight themselves when they arrive and having a plate that won't be used for any other kind of diving.

...

 

[Deep South Divers]

Regarding the weight belt buckle used as a quick release on a harness:

I haven't used one myself... I find that the easiest way to don and doff my rig is to lift it a little and get in and out of the rig sorta "ducking under and out." This works really well if you stand the rig up on the tailgate of a truck or on a picnic table and back up to it (make sure to always have a hand on the valve so it doesn't topple). Duck down a little and you should be in and out very easily. Alternatively, you can have your dive buddy hold your rig from behind while you duck down and back into it.

If this doesn't work, make sure that the harness is fit properly. The shoulder straps should be surprisingly loose in a properly-fit rig... Much looser than what you've come to expect by using a BC. The reason for this is because with a backplate and wing, much of the weight of the rig will be supported on your waist while topside... Not all of it on your shoulders like a regular BC. On a regular BC, there is usually a cummerbund and/or 1" straps and/or plastic buckles on the waist that will not support weight, so the shoulder straps need to support all of the rig's weight. Not so with a bp/wing. Thus, topside, a bp/wing distributes it's weight better than a "regular" BC does, adding to comfort and reducing the need for shoulder padding too. Hikers have known this for years, and know that they can carry a lot more with backpacks that have hard structure and weight-distributing waist straps in them.

Fitment in a backplate and wing is critical. Check DIR-diver.com - Adjust the backplate for proper fitment techniques. Notice picture #3 especially... You should be able to JUST BARELY touch the top of the plate if you reach back for it. The plate should be worn as low as possible, but still allow you to just barely be able to fingertip the top edge of it. If this is the case, those shoulder straps are so loose that getting in and out is as easy as pie, regardless of how you do it.

An indicator that your shoulder straps are too loose is... If, when you are diving, the shoulder straps fall off of your shoulders - ie. you feel like you need a chest strap to keep them on - then they're too loose. Basically, you want them as loose as possible without causing the problem of having them come off your shoulders when diving.

If donning and doffing is still an issue because of a medical issue, then don and doff in the water where the rig is totally weightless and let your buddy haul the rig out for you. He won't mind the 15 seconds of extra work if it avoids taking you to the hospital - or hearing you complain about your aching back. Just remember to compensate by doing a little extra work for him, too... Paying for his gas, carrying his gear, whatever.

If none of the above work for you and you are STILL insistent that you need a quick release system on your backplate and wing, here's how I have rigged one for my guys:

Firstly, make sure that your harness will NOT slip in the backplate. With a Hogarthian harness, I like to use "toothed" triglides behind the backplate like you see here: D-Rings, Belt Slides, and Clamps - Dive Gear Express They call it a "Belt Slide, 2-inch S/S Serrated." I have seen some backplates not require triglides, and I have seen "regular" triglides used, but I prefer to use these "serrated" ones behind the plate. This is the only place on a rig that I use a non-standard triglide - I use standard ones (what they call a "Belt Slide 2-inch SS") everywhere else on the rigs. With a "deluxe" harness, the webbing is usually sewn to the backplate or otherwise looped and captured, and slippage is a nonissue.

On the side that you want the quick release, cut the shoulder strap about 4" above the plate. Use a pair of sharp stainless scissors and burn the edges so they won't fray. Attach the buckle to the backplate side of the shoulder strap, close to the backplate. Threading goes over, under, over and under... Not under, over, under and over. For this application, I do not fold the strap back over and through the buckle again like I do on the waist... I simply leave it as a loose end under the buckle. It fits neater that way, and flatter. Round the long side of the strap with a pair of scissors and burn it that way - in a semicircle - for ease of threading into the buckle, the same way that you'd do on the waist.

Setting the buckle up this way and this low on the rig should not interfere with shoulder D-rings or anything that you would attach to them, including bungieed back-up lights. This quick release system should be lower than that and operate easily with either hand on either side of the rig by flipping the buckle up with your fingertips.

Adding a buckle this way will reduce the shoulder strap's overall length by a few inches. After installing, you will have to readjust the altered shoulder strap to be even with the one that you did not alter. For this reason, I have found that it's less hassle to install a quick release on the right shoulder strap instead of the left one if it's all the same to you... With less hardware to have to move and adjust, it's just easier if you don't care which side gets the quick release. Alternatively, you can also/or alter your left shoulder strap as well or instead if your medical condition requires it.

Most people that I have added a quick release for have ultimately stopped using it altogether and learn to simply duck out of the rig. They say it's easier, quicker and less hassle. But if you really want one, that's the way to do it without adding some piece of crap plastic doohickey on your rig that breaks at the most inopportune time and costs you a dive.

For what it's worth... The guy that I mentioned earlier in this thread that I did the body recovery for... He was wearing a BC that had one plastic quick release on each shoulder. They were worn out and brittle and broken from the strain of him carrying so much weight in his BC... Which was full of lead both in an integrated weight system and in the BC's pockets. As such, he had "fixed" the quick releases by duct taping them shut. This prevented him from being able to doff the rig quickly in his OOA and contributed to his drowning.

He'd have been better off using a weight belt buckle as a quick release... Which would have been made of durable stainless steel, not something that would, over time, wear out and break and require duct tape to stay together.

Alternatively, he could have worn a rig that was designed in such a way that it wouldn't need quick releases at all. Like a backplate and wing rigged with a Hogarthian harness.

None of this would have been an issue for him if he hadn't been diving with 128 lbs of lead on, though... Or if he'd just listened ONCE to any number of people trying to tell him the same thing... Or if he had just not run out of air that day... The list goes on. :-(

Anyway, that's how to do a quick release buckle if you really want to do it... But I would recommend learning effective ways of donning and doffing your rig without the use of one. A properly fit backplate and wing rigged with a Hogarthian harness gives you a fighting chance of exactly that.