BP/W lift?

[Yoyoguy]

Hello everyone. Long time reader. First time poster. I have googled this to death and I did find the "Ultimate lift calculator thing" for wings BUT it will not open for me. I am contemplating converting to a BP/W set-up. I do a lot of cold water diving but I do warm water as well and realize I will likely need two different wings. I am going to start off with a cold water set-up as that is what I dive locally the most. I will wear either a 5mm or 7mm full suit with hood and gloves depending on depth. I am 5'8 ~190lbs (bit of a beer belly haha). I need between 19-23 pounds of extra lead depending on which suit I wear with my current BCD. On deeper colder dives I wear a 7mm full suit and sometimes bring pony bottles ranging from 19-40cu size. Don't ask why I bother with a 40. I got it cheap and use it sometimes slung on my right side. I strictly use aluminum 80s at the moment but I am considering switching to steel tanks at some point and maybe a dry suit will be in my future. From all the info I have read...a 30lb wing should work for these needs? I was originally looking at the hollis wings but they only have a 25 and 38. Would the 38 be overkill? Hollis is about the top end of my price range. I have also looked into the 32 hog as well. I do like the hollis better though for the red and black color as silly as that may sound. I am just at odds with what lift I will need. I know there are no guarantees until I actually get one and figure it out. I realize I will be ditching some of the lead when converting to the backplate wing set-up, just giving you all the current info I have. Could someone punch this into a calculator for me if they can get it to work. Not sure on any other info you may need. Thanks.

 

[Jim Lapenta]

HOG also comes in red and black. a 32 would work for all your diving. A steel plate is going to let you take off 6 lbs of lead from the get go. If you are using a BC with a good deal of padding that may also save you another 3-6 lbs since a BPW does not have that inherent buoyancy.

No need for a calculator. I use a 32 for all single tank diving. From al 80's in a skin to LP 95's in a dry suit.

 

[Tony387]

I agree with what Jim said...however, if I was diving deep and wearing a 7mm, particularly with steel, (plenty of threads on that subject) I might want a little more lift. Just my opinion.

 

[Yoyoguy]

HOG also comes in red and black. a 32 would work for all your diving. A steel plate is going to let you take off 6 lbs of lead from the get go. If you are using a BC with a good deal of padding that may also save you another 3-6 lbs since a BPW does not have that inherent buoyancy.

No need for a calculator. I use a 32 for all single tank diving. From al 80's in a skin to LP 95's in a dry suit.

Thanks Jim. That is basically what I have read.

I agree with what Jim said...however, if I was diving deep and wearing a 7mm, particularly with steel, (plenty of threads on that subject) I might want a little more lift. Just my opinion.

Tony...I was also wondering this as well. I don't know what you consider deep but I am only deep diver certified (130ft)...no tech diving for me (yet). I have been to 120ft with 7mm suit, hood, gloves, large flashlight with spare one in my BCD and sealife camera system with strobe and video light, which I know can all add to the amount of lift you may want or need. Of course if lift became an issue, you could ditch a few pounds of extra weight. This is where my concern would lie. I don't mind having a slightly larger wing in this scenario.

thoughts?

 

[eelnoraa]

This topic comes up too often. The key is that wing lift should compensate for things that change in buoyancy. So in this case, it will be the 7mm suit + gas. The flash lights you are carrying should be compensated by the ballast you are carrying. Not by a bigger wing. You camera should be weighted more of less neutral to begin with, so that shouldn't be an issue either.

Another considering is wing being able to float your rig without you in it. For cold water, this has more to do with where you are carrying your weight. If you put all your weight integrated, you will need a bigger wing. If you are willing to use a weight belt, you wing doesn't have to be as big.

To be precise, the first thing you should do is to determine the buoyancy of your suit. Having that said, I agree with Jim, 30-35 is a good number. Usually provide enough lift and still streamline.

 

[Yoyoguy]

This topic comes up too often. The key is that wing lift should compensate for things that change in buoyancy. So in this case, it will be the 7mm suit + gas. The flash lights you are carrying should be compensated by the ballast you are carrying. Not by a bigger wing. You camera should be weighted more of less neutral to begin with, so that shouldn't be an issue either.

Another considering is wing being able to float your rig without you in it. For cold water, this has more to do with where you are carrying your weight. If you put all your weight integrated, you will need a bigger wing. If you are willing to use a weight belt, you wing doesn't have to be as big.

To be precise, the first thing you should do is to determine the buoyancy of your suit. Having that said, I agree with Jim, 30-35 is a good number. Usually provide enough lift and still streamline.

I get what you mean about the camera and flashlights. Or at least I think you do. You are saying that if the dive lights and camera added 3lbs to sinking, then I should in theory remove 3lbs of lead to compensate. I did not think about that. As far as being able to float your wing. I honestly have no idea where all my weight will end up. Currently I carry 16lbs on my current weight belt with an additional 4-6lb in BCD depending on what im wearing. That is just because I got the weights and weight belt for free when I started but honestly...I do trim out pretty well in this set-up and do not mind the weight belt as some others do. However, from what I see here, a big plus to the BP/W setup is being able to carry less weight on your person Now I am even more confused haha.

 

[JBFG]

I dive a HOG 32# wing.
Dry suit, AL plate and AL80 tanks.
no issues for me.

I think a 32# is definitly ideal for my cold water diving

 

[Patoux01]

Reasons to use of the lift of a wing:
- failure of a drysuit (just know how much buoyancy that represents). I am NOT recommending to use drysuit as bcd, it simply has some inherent buoyancy that it will lose in case of complete failure.
- compression of a neoprene suit (usually not more than 2kg I'd say...)
- gas in your tank(s)
- potentially assisting a buddy, which doesn't require much (I don't count this when we both dive drysuits)

With the usual tank being maybe 5kg of air (depends where you are, since some will use 15l and others 10...), there's really no need for a lot.
Imo even 10l (probably around 20 pounds?) is enough. But don't let the fans of the manta-look hear that, as it won't let you look as manta-ish as they do with their heavily oversized wings flapping around proudly
If you're planning on diving twins soon, you could look at something a bit bigger, eg 15-20l (which is more than enough for a twinset + deco tank).

On a side-note, I haven't looked at the wings mentionned here, but don't forget that if the volume has its importance, its distribution is also very important.

 

[halocline]

- compression of a neoprene suit (usually not more than 2kg I'd say...)
- gas in your tank(s)
- potentially assisting a buddy, which doesn't require much (I don't count this when we both dive drysuits)

7mm wetsuits can lose quite a bit more than 2KG of buoyancy when fully compressed, probably more like 6-8KG. The most conservative way of determining your wetsuit's potential buoyancy loss is to put it in a mesh bag and see how much weight it takes to sink it. This is it's total buoyancy, and cannot lose more than that amount.

Please do not size a wing with additional lift to assist another diver. Rescue protocols specify using the other diver's own BC, dropping weights, or a combination of the two. There was recently a big thread on this very topic.

 

[cool_hardware52]

Hello everyone. Long time reader. First time poster. I have googled this to death and I did find the "Ultimate lift calculator thing" for wings BUT it will not open for me. I am contemplating converting to a BP/W set-up. I do a lot of cold water diving but I do warm water as well and realize I will likely need two different wings. I am going to start off with a cold water set-up as that is what I dive locally the most. I will wear either a 5mm or 7mm full suit with hood and gloves depending on depth. I am 5'8 ~190lbs (bit of a beer belly haha). I need between 19-23 pounds of extra lead depending on which suit I wear with my current BCD. On deeper colder dives I wear a 7mm full suit and sometimes bring pony bottles ranging from 19-40cu size. Don't ask why I bother with a 40. I got it cheap and use it sometimes slung on my right side. I strictly use aluminum 80s at the moment but I am considering switching to steel tanks at some point and maybe a dry suit will be in my future. From all the info I have read...a 30lb wing should work for these needs? I was originally looking at the hollis wings but they only have a 25 and 38. Would the 38 be overkill? Hollis is about the top end of my price range. I have also looked into the 32 hog as well. I do like the hollis better though for the red and black color as silly as that may sound. I am just at odds with what lift I will need. I know there are no guarantees until I actually get one and figure it out. I realize I will be ditching some of the lead when converting to the backplate wing set-up, just giving you all the current info I have. Could someone punch this into a calculator for me if they can get it to work. Not sure on any other info you may need. Thanks.

If you are diving only cold water it having a bit more wing than you need won't matter much.

However if you want to use one wing for warm and cold water diving it's worthwhile to determine carefully what you need for cold water.

That helps you avoid having a wing that is far larger than necessary when you go some place warm and sunny.


A couple quick points:

Your personal buoyancy may impact total weighting, but personal buoyancy doesn't change with respect to depth, and doesn't need to be "compensated" for.

Planned depth isn't really a player either, unless you will always be over a hard bottom of limited depth.

This puzzle starts with the buoyancy of your suit, test it. It's a number you need anyway for weighting calc's

Tobin