Diving Doubles?

[PerroneFord]

I guarantee, if you do a search for "bp/w" you will have more hits than you can read in a month.

The BP/W is very modular. Unlike a normal BC, the plate is metal (you can give it to your grandkids and it'll still work like new), the webbing is $1 a foot and you need 12-14ft, and the only real expense is the wing, which you switch out depending on what tanks you're using. Two screws, and the wing is off. You don't even have to readjust the harness sizing to change wings. I go from my single to my double tanks in about 2 minutes.

Why won't 27# be enough lift for you? And I can't IMAGINE a 36# wing not being enough. Are you carrying bricks in your pockets? Assuming your rig is balanced, you'll be neutral at 10ft when your tank is near empty. So the only thing making you negative as you dive is wetsuit crush (this is mitigated with a drysuit) and the weight of the gas in your tanks, which shouldn't be more than 4-10 pounds depending on what tank(s) you're using. So given that, unless you start carring 3-4 tanks on your dives, 27-36 pounds is CERTAINLY more than enough.

Someone REALLY needs to make a sticky of the companies doing BP/Ws as well as a comparison grid.

Many of us here tend to recommend products by DeepSeaSupply or Oxycheq because the owners participate on this board and they have great products. Golem Gear is another company that makes a very good BP/W at a fair price and the owner participates here. Dive Rite, OMS, and Halcyon also make good BP/W systems. There are others but these seem to be the most popular, and with good reason.

If you intend to dive doubles at some point, leave the jacket BC's alone. They just won't do the job or make it FAR harder to do the same job.

Duh! I can't believe I didn't even think of ebay for my BC, even though I'm constantly watching it for every other piece of gear imaginable. One of the things I couldn't help but notice is that everyone seems to be after Halcyon's 27# wing, but on Halcyon's site they don't exist. I know 27# almost certainly wouldn't be enough lift for me (diving a single tank), but the same goes for a 36# - I can't find those anywhere on their site either.

To go from singles to doubles, all you have to do is bolt on bands and get a wing that has enough lift though? I definitely like the modularity (There's a word for you..) of a bp/w over a jacket BC. Do you have any websites that have OMS or Halcyon (or any other company who makes bp/w's) gear for sale? I almost can't find prices, much less compare shops for a better price..

 

[CuriousRambler]

Whoops, I thought you were misunderstanding me, but I reread my post and I completely worded that wrong haha. I meant the same goes for a 36# wing as in I can't find them on Halcyon's website, not that it wouldn't be enough lift for me. Sorry about that.

From reading everything I could find on determining wing size and bouyancy required, 27 seemed to be cutting it close for me, if even having enough to "cut it close" and not just be too little. Cold, fresh water, 7mm wetsuit and AL80. I didn't do any calculations, but going off the endless examples and "picture this"s that have already been posted, I got a pretty clear impression that 27# wouldn't quite be enough to dive locally.

As for the companies who make them, I've seen websites for just about all you listed, but many of them don't have prices. I was asking more for stores online that carry their products so I can see prices and get an idea of what I'm going to end up spending.

 

[Mark Vlahos]

Deep Sea Supply complete single tank rig with Hogarthian harness $445.

What kind of standard BC are you looking at? Would that BC be a good choice for doubles, or would you still need the plate and wing? Remember, when switching from singles to doubles with a backplate you may only need to change the wing.

Mark Vlahos

 

[PerroneFord]

LOL! Ok, simple misunderstanding.

Yep, if you're diving a 7mm wet, 27 might cut it close.

So try this:

http://www.fifthd.com/index.php?main_page=index&cPath=1_11

http://www.deepseasupply.com/page12.html (Hog Harness)
http://www.deepseasupply.com/page21.html (Torus 35)

http://www.oxycheq.com/Wings-Razor.html

http://www.golemgear.com/pc-165-2-golem-35-lbs-ss-combo.aspx


That should put you in the ballpark

Whoops, I thought you were misunderstanding me, but I reread my post and I completely worded that wrong haha. I meant the same goes for a 36# wing as in I can't find them on Halcyon's website, not that it wouldn't be enough lift for me. Sorry about that.

From reading everything I could find on determining wing size and bouyancy required, 27 seemed to be cutting it close for me, if even having enough to "cut it close" and not just be too little. Cold, fresh water, 7mm wetsuit and AL80. I didn't do any calculations, but going off the endless examples and "picture this"s that have already been posted, I got a pretty clear impression that 27# wouldn't quite be enough to dive locally.

As for the companies who make them, I've seen websites for just about all you listed, but many of them don't have prices. I was asking more for stores online that carry their products so I can see prices and get an idea of what I'm going to end up spending.

 

[cool_hardware52]

Duh! I can't believe I didn't even think of ebay for my BC, even though I'm constantly watching it for every other piece of gear imaginable. One of the things I couldn't help but notice is that everyone seems to be after Halcyon's 27# wing, but on Halcyon's site they don't exist. I know 27# almost certainly wouldn't be enough lift for me (diving a single tank), but the same goes for a 36# - I can't find those anywhere on their site either.

Cheetah,

27 lbs might not be enough lift for you. I see you live in Montana. Where do you dive?

Any BC neededs to do things; Float your rig at the surface without you in it, and compensate for the loss, or potential loss of buoyancy of your exposure suit.

You can pretty accurately estimate the weight of your rig. The buoyancy of the tanks you are using can be found many places on the web, and the weight of the Backplate, regs, canister light etc. + any addition ballast you might attach to the rig are either known values or can be estimated fairly closely. Just add up all the weights.

Here's a quick example. HP 100 full -10, SS Backplate -5, Harness -1, Regs -2, Can light -3, total -21 lbs.

Now for the exposure suit. For a wetsuit, rollit up, throw it in the pool, add weight until it just sinks. For a big guy in a full 7 mil suit, + maybe a jacket or vest, it can require 25-28 lbs, amybe more. For a small fit person in a 5 mil, much less.

For a drysuit I like the diver to put on their undergarment and suit and get in the pool, vent all the gas you can. Now add lead until the diver is neutral. This weight represents the max buoyancy the diver could loose in the event of a total flood, unlikely, but still worth knowing.

For cold water single tank diving it is almost never the weight of the rig that determines the required minimum lift, it's the exposure suit. There's a reason wings get bigger the further you get from the equator.

To go from singles to doubles, all you have to do is bolt on bands and get a wing that has enough lift though? I definitely like the modularity (There's a word for you..) of a bp/w over a jacket BC. Do you have any websites that have OMS or Halcyon (or any other company who makes bp/w's) gear for sale? I almost can't find prices, much less compare shops for a better price..

When you move to doubles you keep the backplate, and harness. What changes is the wing. A doubles wing isn't just higher lift than a singles wing, it's a different shape, to accomodate the wider doubles tanks. Calculating the necessary lift for doubles is basically the same, but you need also consider the greater weight of gas you can potentially consume.

To set up tanks as doubles you need a manifold, and compatible bands. The move to doubles is not trivial. More regs, bands, manifolds, tanks, new wing, more training.


Good luck,



Tobin

 

[CuriousRambler]

Thanks guys!

Mark: I'm looking at the Oceanic Chute and the Oceanic Probe. I'm not sure about the Chute because Oceanic doesn't have it on their site anymore, just checked it out in my LDS and I kind of like it, probably going to dive my AOW with it and see how it feels. Anyway, on Oceanic's site there's a double tank bracket available for about $120 in the accessories when you're looking at the Probe, as seen here.

I'll have to dig around and see if the Chute can take the same bracket or not. I've got my fingers crossed that maybe one of the local instructors is diving a BP/W so I can ask if they'll let me try it out. From what I've read and seen, I think I'd rather have a BP/W, but $500 isn't exactly casual money to me, so I want to be sure before I buy one, y'know?

 

[CuriousRambler]

Tobin, you posted while I was typing (doing homework, it took me a few minutes to type haha) I haven't taken any dives locally yet, I'm kind of holding off until I can get into my AOW and do the first couple under some supervision since I've never dove anywhere but Maui. The conditions are going to be just slightly different haha. I also want to take my altitude diving specialty so I know what's going on before I jump in and take a DCS hit because I planned for sea level.

I'm up near Glacier Park though, so I imagine I'll get into the park some, as well as Flathead Lake. I only know of a few actual dive sites around here where there's anything to see, and most of them are up in Glacier, so I can definitely see a few trips up there.

 

[cool_hardware52]

Thanks guys!

Mark: I'm looking at the Oceanic Chute and the Oceanic Probe. I'm not sure about the Chute because Oceanic doesn't have it on their site anymore, just checked it out in my LDS and I kind of like it, probably going to dive my AOW with it and see how it feels. Anyway, on Oceanic's site there's a double tank bracket available for about $120 in the accessories when you're looking at the Probe, as seen here.

I'll have to dig around and see if the Chute can take the same bracket or not. I've got my fingers crossed that maybe one of the local instructors is diving a BP/W so I can ask if they'll let me try it out. From what I've read and seen, I think I'd rather have a BP/W, but $500 isn't exactly casual money to me, so I want to be sure before I buy one, y'know?

Oceanic builds fine gear. Nice regs. Good stuff. I have a couple.

I don't know anybody diving doubles who isn't using a BP&W. If doubles are on your "to do" list my best advice is to get started with a BP&W.


Tobin

 

[BarryNL]

I swear I saw a post on this at one point, but as usual, the search function doesn't return much of anything for me.

Anyway, I'm curious about diving doubles. Obviously for penetrations and such people use doubles, but there seems to be a gap somewhere, at least as far as I see. Double tanks don't seem to me like it's one of those pieces of equipment you just pick up and figure out like a spool or new camera, but where do you actually get introduced to diving doubles? Do you get your first experience with it in cave/wreck penetration or deep diving classes? I obviously don't know what certifications every diver out there carries, but there seems to be at least a decent number of "standard" rec divers toting doubles, who appear to have no tec training.

I don't plan on jumping into them yet, I've got plenty to work on before that, but I see no harm in learning about something, even if you have no plans to partake in it in the near future. What course (if any) introduces you to diving doubles, isolation manifolds, etc?

Well, the PADI route is the DSAT Tec Diving course.

A far as working it out for yourself, there's no real reason not to buy a set of double 7s - this still gives you less gas than a single 15 litre but probably better balance. There's not real problem diving doubles, if anything it's easier and more stable than diving a single, plus you can probably forget needing a weight belt - although for this reason you should think about having redundant buoyancy.

The real reason to get training before going to double 10s or higher is that you can easily go into decompression long before you get low on air but then find you don't have enough to do the necessary deco stops, and possibly the skills to do deco stops properly. Again, provided you are always careful to stay out of deco there's not real reason to stay away from doubles; just make sure you have sufficient buoyancy in the case of a drysuit flood or BCD failure.

 

[PerroneFord]

I don't know anybody diving doubles who isn't using a BP&W. If doubles are on your "to do" list my best advice is to get started with a BP&W.


Tobin

Ditto. If you're going to dive doubles, don't waste time or money fooling with anything else. You'll just regret it on the long run.