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nns91
December 27th, 2009, 02:15 PM
I am an inexperienced diver looking for my first BP/W set up. I am looking at the DiveRite Transplate with steel backplate. For wing, I am looking at the Oxycheq Mach V. I am going to dive single tank but unable to decide whether I should go for 40lbs or 30lbs of lift. I am 120lbs. I know there is a calculator but I have no clue how to use it so can anyone help me ?

deadly_risk
December 27th, 2009, 02:25 PM
I love my DSS (https://www.deepseasupply.com/) setup, and would suggest you contact Tobin ( cool_hardware52 (http://www.scubaboard.com/forums/members/cool_hardware52.html) )

Deep Sea Supply - ScubaBoard (http://www.scubaboard.com/forums/deep-sea-supply/)

paddler3d
December 27th, 2009, 02:33 PM
30#'s of lift is fine for just about any single tank. The advantage of getting the smaller wing vs. something larger is the smaller wing will be nice and streamlined. One of the joys of BP/W setups is that you can change the wing in the future as your needs change.

fisheater
December 27th, 2009, 02:35 PM
It many depends upon your exposure protection. You need enough lift to compensate for the loss of buoyancy that your exposure protection experiences due to depth.

nns91
December 27th, 2009, 02:38 PM
No matter whether it is steel of aluminum ? I will be diving at different places so I kinda need some flexibility. Plus, 30lbs will be enough even when I carry some extra things like light,...

paddler3d
December 27th, 2009, 02:46 PM
Most traditional BC provide a max of 30#'s of lift. A lot are in the low to mid 20's.

If you get a bigger wing, you run the risk of the wing tacoing around you tank, making buoyancy control tougher, and the bigger wing will increase drag causing your air consumption to increase.

If you see yourself diving with pony bottles and such, the 40# wing may make more sense.

A 30# wing should give you enough lift for a single tank, steel or AL, lights, compasses, so on so forth.

nns91
December 27th, 2009, 03:25 PM
oh ok, so does that mean some BCDs have too much lift capacity ? For example, I have seen Mares Dragon has 44lbs, Oceanic Probe LX 26-54lbs (depends on size).

GrumpyOldGuy
December 27th, 2009, 03:47 PM
I purchased a 40lb Mach 5. It will NOT taco, it is a narrow low profile wing. It is however bigger than any normal person would need for a single tank. I swapped it for a 30lb Mach 5 wing, perfect size. I am a a big guy 220lbs, XL, lots of 7/7 FJ+jacket neoprene and I do not come close to maxing it out.

Many BCD have over sized wings because you load them down with so much lead. The all-in-one integrated concept has its cost, not just dollars but bulk and weight. The BP/W tends to be minimalist and needs less lift, thus less drag, less bulk....

paddler3d
December 27th, 2009, 03:48 PM
At the beginning of this forum is a Sticky on Lift Calculations.

http://www.scubaboard.com/forums/buoyancy-compensators-bcs-weight-systems/158370-ultimate-wing-lift-calculator.html

I don't know how to link to this in the message.

However the first poster has a link to some excel spreadsheets that will help you do the math taking into account everything.

Here in the US we definitely have the mentality that bigger is better. Not very one likes the BP/W combo so they make BCD's that have a lot of lift. Is it necessary? Maybe, maybe not.

Years ago I started in a DR SS Transplate with a Rec wing. It had something like 50+#'s of lift.

Quickly I ditched the harness system it came with and went with a simple one piece harness.

For a couple of hundred dives I felt like my buoyancy was never perfect. I felt like I was always being rolled to one side or the other and I was always having to scull with one foot or the other to level myself out.

One day I grabbed by buddies set up. Nearly the same except he had a 30# wing on it. My buoyancy was spot on. I could lie there motionless. I think the tank I had on was the HP117 steel tank.

Air consumption also improved.

Now I have a 30# travel wing for singles and a 60# classic wing for my doubles.

Look at what tank you likely going to be diving and its buoyancy characteristics, and a couple of pounds for a light, so on so forth. Once you do the math, you may find that 30#'s is a lot.

Since you're doing a BP/W combo you're likely going to have a D-ring on your butt. This is a great spot to attach a dive reel and lift bag. A lift bag where you can manually dump the air acts like a redundant BC.

Also remember that a proper weight check will also show you that your wing is, I don't want to say irrelevant, but isn't as crucial until you start diving doubles and stage bottles. When you tank is low (500psi) you should be able to have a completely empty BC and bob at eye level purely by holding your breath. If you can do that, you're just about perfectly weighted.

nns91
December 27th, 2009, 03:53 PM
Thanks a lot. I have noticed the calculator but to be honest, I don't really know how to use it so I am posting a thread hoping you guys, experienced divers, can help me.

A reason I want to go for BP/W is that it is less bulky and customizable so it is true that I don't want something way much more than I need.

paddler3d
December 27th, 2009, 05:52 PM
Fill out your profile more and that will help folks with advice.

paddler3d
December 27th, 2009, 06:16 PM
When you open up the calculator you'll see some fields on the left hand side that are blue.

They include Head weight, Tank Full, Tank Empty, Suit, BP, Light, Doubles?, and Weight Intergrated.

Apparently the head weight approx 8% of your body weight. You can do the math on that.

There is a table with the most common tank sizes on it, where it has the tank size and then full and empty. Air has mass so a full tank is going to weigh more than an empty tank. Steel tanks typically are very negatively buoyant when full and slightly negatively buoyant when empty. Aluminium tanks start off negative and then end up positive. Assume that you'll be diving an AL80. Fill in the buoyancy for that.

DR SS plates are around -5#. Pop that in there.

Assume a non-canister light is going to run our -2#'s.

You're not diving doubles so enter '0'.

You're not diving Weight Intergrated, so again '0'.

If you go to the websites of various wetsuit manufactures, you can typically find the buoyancy characteristics of various wetsuits. Input the info you find.

The spread sheet will then tell you the amount of lift you need in Red.

Seriously, update more of your profile and describe where you see yourself diving.

Amphibious
December 27th, 2009, 06:27 PM
I love my DSS (https://www.deepseasupply.com/) setup, and would suggest you contact Tobin ( cool_hardware52 (http://www.scubaboard.com/forums/members/cool_hardware52.html) )

Deep Sea Supply - ScubaBoard (http://www.scubaboard.com/forums/deep-sea-supply/)

+1 been using a DSS wing for a few years now, huge fan.

JThompson
December 27th, 2009, 06:42 PM
Im 6'4" and 280lbs. I dive the Dive Rite Transplate, Oxycheq Mach V Extreme 30, SS Dive Rite backplate and Dive Rite STA. I dive in southern ca where a 7mm is just about always required. I also occasionaly dive lake mohave in AZ where the water temp in the summer is 85+ and in the winter gets down to 48. I use single steel and aluminum tanks. Even with all my different kinds of diving my set up works just fine so I know that the 30lbs wing will be just fine for you. And yes most manufactures that make jacket style BCs like the Aqua Lung pro qd, in my size (xxl) 54lbs of lift, has way to much lift for MOST divers out there. Im sure for some divers 54lbs of lift is just what they need but for the most part its overkill. Hope this helps.

nns91
December 27th, 2009, 07:02 PM
This definitely helps. Thank you so much. I am much smaller than you and only use a 5mm wetsuit so I guess 30lbs will be the way to go for me.

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