Are the Super Wings too much?

[headhunter]

At 6 ata (6 x 33=198 ) ( 198 - 33=165 fsw) ( 6 x 14.7= 88.2 lbs psi) that's a whole lot of water pushing down . now lets take into account that the air in the bladder is now 1/6 the volume it was on the surface, and my guess would be - the diver needs more lift to stay neutral.

I could be wrong,but that doesn't happen often

OK, I'm back from my jaunt.

I see what you're saying, but it would not make a difference.

The air in a tank does not become heavier under pressure. When you fill a tank at surface, it becomes heavier because you squeeze more air into the same amount of space.

For instance, if you have a 100 cu ft tank, that means that you are taking the amount of air that uncompressed would fill a room that contains 100 cu ft. and squeezing that air into a space the size of your tank. The "amount" of air would weigh the same, since it is still 100 cu ft. However, it would displace a different amount of space. By the way, that would be a pretty small room! The floor would be 2 ft x 5 ft and it would have a 10 ft ceiling!

So, when your tank is full, the air that is in it weighs the same amount no matter what depth it sits at. The tanks bouyancy would be the same at depth because the tank is rigid and does not change like a balloon would. If that same air were in a balloon, the air would still weight the same amount, but would displace less space in the water and therefore be less bouyant.

I hope that made sense.

Christian

 

[msandler]

55lbs of lift (unsure of the exact volume of salt water displaced when full) will do the job 90% of the time and becomes insufficient as follows (speaking from experience):

With double 120's on a SS plate and a pair of 40's (all tanks at 3500psi), wearing a 3mm, and no weight, carrying lights, reels yada yada yada, I "smart bombed" the Sucre (215' in under 2min.) I avoided the sand by inches when I neutralized my bouyancy. I reached behind to feel the wing, it was full (probably a few shots shy of dumping air).

Very entertaining thread

 

[eastcoastdiver]

I am about to begin tech training, and I needed to know a little bit of info about a bc setup. I am planning on purchasing the Dive Rite steel back plate and harness, but I can't decide on the wings. I will currently be using my bc with al 80 doubles, but in the future I would like to do some cave diving with pressed steel 104s and some decompression bottles. Obviously the Dive Rite Super Wings would be great for the cave diving, but are they too much for double al 80s? Thanks for your help! (And be nice to me, this is my first post!)

Dive Rite's recommended air cell for double al80's is the Trek wing. It has 40 lbs of lift.

For double lp 104's they recommend the Rec wing 51 lbs or the classic wing 59 lbs.

The super wing has 77 lbs of lift and is recommended for double lp 120's lp 131's.

 

[decoeric]

55lbs of lift (unsure of the exact volume of salt water displaced when full) will do the job 90% of the time and becomes insufficient as follows (speaking from experience):

With double 120's on a SS plate and a pair of 40's (all tanks at 3500psi), wearing a 3mm, and no weight, carrying lights, reels yada yada yada, I "smart bombed" the Sucre (215' in under 2min.) I avoided the sand by inches when I neutralized my bouyancy. I reached behind to feel the wing, it was full (probably a few shots shy of dumping air).

Very entertaining thread

Speak for yourself about entertaining... I have gotten kicked around pretty good.... Oh well live and learn... I remember now why I don't like message boards...

 

[jagfish]

air compresses at depth. that compressed air now weighs more. ( just like a full tank weighs more than a empty tank) and there is less volume.

While your point that the air needed to fill the wing would weigh more at depth is technically true, the extra weight of the air compressed to 6ATA would be negligible as one poster has already pointed out.

have you ever taken a tennis ball to 100 feet, It will be crushed yet return to normal at the surface.

This last point really has no relevence to the discussion that I can fathom. A tennis ball cannot be refilled at depth back to original capacity while a wing can...Unless you are just trying to illustrate that air is denser at depth, which as above, is true. However, once again, the weight of 2 or 3 gallons of 1ATA air and 6ATA air is not significant in this case...

 

[The Kraken]

Unless the wing generates an unacceptable wrapping situation what does it matter that he dives a 100# lift bladder?

 

[jagfish]

Unless the wing generates an unacceptable wrapping situation what does it matter that he dives a 100# lift bladder?

I'm inclined to agree Krack,
However, the issue here at the moment was not whether the 100 has too much lift, but whether the 55 has enough...

 

[novadiver]

I'm inclined to agree Krack,
However, the issue here at the moment was not whether the 100 has too much lift, but whether the 55 has enough...

I beleave the question was about entry level tech diving. I think that in entry level that the 60# wings would be more than enough. If there is the need to take multible deco bottles and a scooter , than the 60# wing would fall short of the lift needed to bring a dead scooter and all the bottles to the surface. Not to mention a dive buddy with a ripped drysuit and damaged wings.THen even the 100# wings might not be enough

 

[The Kraken]

Good point, Nova . . .
If one follows the concept of being totally redundant, then it would follow that the lift capacity of one's bladder should be sufficient to support not just one, but two divers at the surface.

 

[msandler]

I beleave the question was about entry level tech diving. I think that in entry level that the 60# wings would be more than enough. If there is the need to take multible deco bottles and a scooter , than the 60# wing would fall short of the lift needed to bring a dead scooter and all the bottles to the surface. Not to mention a dive buddy with a ripped drysuit and damaged wings.THen even the 100# wings might not be enough

ripped suit and damaged wings - not likely but I guess that's risk management for some. I would not be worried about the scoot and other items (lights, stages, etc.) that can be sacrificed for bouyancy in an emergency either collectively as a team or individually.