iv been lookin at a different setup, thinkin of switchen to twin aluminum 80`s, with a sea elite tech ballistic bcd. my question is this, how much lift would i need, will i need more or less weight? has any one used this type of bc/setup before, if so how did it work? the bc is weight integrated, back bouyancey, and comes ith either 60lb or 85lb air cell. i`m 6`2 195lbs, if that helps any.
wonderin what to buy??
- Thread starter mongrol
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mlove
Contributor
mongrol,
I never understood bc advertising that brags about different lift specs. If you were only adding enough weight to make yourself slightly negatively buoyant, why would you need a lot of lift?
mike
I never understood bc advertising that brags about different lift specs. If you were only adding enough weight to make yourself slightly negatively buoyant, why would you need a lot of lift?
mike
mlove
Contributor
mongrol,
By the way welcome to the forum. I have found this a great place to learn and share.
mike
By the way welcome to the forum. I have found this a great place to learn and share.
mike
i see your point,just wonderin what peoples opinions were on the two different sizes, my fault i didnt explain myself. i`m more interested on how much more weight i`ll need and if this type of bc is a descent one. what the advanages and disadvantages are of twin tanks other then a longer bottom time.if anyone has hd a bad experience with this style of setup.
Lost Yooper
Guest
Sixty pounds of lift is plenty for double AL tanks as well as double LP steels. A single 80 empty is 4lbs+, so two 80's is 8lbs+ which means you'll need to add 4lbs more weight.
I don't use double 80's, so I can't comment on their balance and what not, but in general, I don't like the positive effect they get when the get low. They are the double tanks of choice for wet suit divers due to their positive buoyancy charateristics.
I would highly recommend a back plate, wing, and harness BC -- particulary Halcyon. I'm not familiar with the BC you've mentioned, but I like the Halcyon so much, I feel compelled to recommend it any chance I get.
Good luck.
Mike
PS. I haven't seen to many ditchable weight integrations that impressed me.
I don't use double 80's, so I can't comment on their balance and what not, but in general, I don't like the positive effect they get when the get low. They are the double tanks of choice for wet suit divers due to their positive buoyancy charateristics.
I would highly recommend a back plate, wing, and harness BC -- particulary Halcyon. I'm not familiar with the BC you've mentioned, but I like the Halcyon so much, I feel compelled to recommend it any chance I get.
Good luck.
Mike
PS. I haven't seen to many ditchable weight integrations that impressed me.
Hey Mongrol,
Welcome to the board - I will second Mike on the setup and the thoughts on using AL80's - I dive LP104's and they are great.
With AL80's or steel 60 lbs of lift is more than enough...
Consider this:
How much weight do you need at the surface to be slightly negative when you have vented all air from your suit and the bc?
I don't know about you - I'm 6' 2" and about 200#'s - so we are in the same ball park - I dive a shell suit and with a single LP104 I need about 17#'s to be neutral on the surface...
Add to that that when my tank is full I have an extra 6#'s of weight with me - so, the amount of lift I need to keep me from drowning on the surface with a full tank - would be about 6#'s - remember - you are supposed to be neutral with a tank that is around 500 PSI.
In your case you would have to change the math a little bit - your tank is going to be positive when empty - +4#'s - but since you already have that weight on when you are neutral - you should still only need about the weight that your air is...
Now - this all assumes that you just want to be neutral in the surface - if you want to lift yourself out of the water you need a bit more lift - but as you can tell - you really don't need a lot of left - I would recommend along with Mike that you look at something like the Halcyon backplate and wing setup - it is SWEET - nothing to break - no gizmo's and stuff you don't need and if you need them - you can add it easily...
Also - to learn more aobut the weighting and trim issues - pick up the book "Fundamentals of diving" from http://www.gue.com
Mike - would you care to tell me if my math is anywhere near right - I have this notion that I'm missing something.
Cheers,
Big T
Welcome to the board - I will second Mike on the setup and the thoughts on using AL80's - I dive LP104's and they are great.
With AL80's or steel 60 lbs of lift is more than enough...
Consider this:
How much weight do you need at the surface to be slightly negative when you have vented all air from your suit and the bc?
I don't know about you - I'm 6' 2" and about 200#'s - so we are in the same ball park - I dive a shell suit and with a single LP104 I need about 17#'s to be neutral on the surface...
Add to that that when my tank is full I have an extra 6#'s of weight with me - so, the amount of lift I need to keep me from drowning on the surface with a full tank - would be about 6#'s - remember - you are supposed to be neutral with a tank that is around 500 PSI.
In your case you would have to change the math a little bit - your tank is going to be positive when empty - +4#'s - but since you already have that weight on when you are neutral - you should still only need about the weight that your air is...
Now - this all assumes that you just want to be neutral in the surface - if you want to lift yourself out of the water you need a bit more lift - but as you can tell - you really don't need a lot of left - I would recommend along with Mike that you look at something like the Halcyon backplate and wing setup - it is SWEET - nothing to break - no gizmo's and stuff you don't need and if you need them - you can add it easily...
Also - to learn more aobut the weighting and trim issues - pick up the book "Fundamentals of diving" from http://www.gue.com
Mike - would you care to tell me if my math is anywhere near right - I have this notion that I'm missing something.
Cheers,
Big T
Lost Yooper
Guest
Looks good to me 
. I'll put things in perspective a bit. The WKPP (the most extreme group of cave divers on the planet) use DUI TLS300 dry suits, double PST 104's (-25lbs full), Halcyon SS BP (-6lbs), up to four Al 80's slung, and a great big EE canister light ((-8lbs?). They use a single 55lb Halcyon bladder and are weighted such that they can ditch enough stuff to swim the tanks up from depth. I'm not talking about the scooter divers, but the safety divers.
I use double PST 95's, shell suit, 10lb V-weight, and a stage for most dives, and I use the 55lb wing. Double 80's won't require 55lbs of lift -- probably closer to a 36lb wing (?), so you can add a cannister light and some stages later. A 55lb wing will work, of course, but you can get a better matched system with a Halcyon type of BC. Ultimately, you want a match between your needs and your wing. Too much lift (or improper weighting) basically translates into more unnecessary drag and, therefore, increased workload and air consumption. Everything is dependant on something else in diving.
Take care.
Mike
. I'll put things in perspective a bit. The WKPP (the most extreme group of cave divers on the planet) use DUI TLS300 dry suits, double PST 104's (-25lbs full), Halcyon SS BP (-6lbs), up to four Al 80's slung, and a great big EE canister light ((-8lbs?). They use a single 55lb Halcyon bladder and are weighted such that they can ditch enough stuff to swim the tanks up from depth. I'm not talking about the scooter divers, but the safety divers.I use double PST 95's, shell suit, 10lb V-weight, and a stage for most dives, and I use the 55lb wing. Double 80's won't require 55lbs of lift -- probably closer to a 36lb wing (?), so you can add a cannister light and some stages later. A 55lb wing will work, of course, but you can get a better matched system with a Halcyon type of BC. Ultimately, you want a match between your needs and your wing. Too much lift (or improper weighting) basically translates into more unnecessary drag and, therefore, increased workload and air consumption. Everything is dependant on something else in diving.
Take care.
Mike
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