LDS says My Torus 26 doesnt have enough LIFT

[DivingPrincessE]

I do have to wonder what your goals are in making such a post. How does it add to the discussion?

Maybe to advise you that you might want to be more considerate of your tone when dealing with your customers, IJS.

 

[MonkSeal]

Although OP didn't specifically asked my advice nor I have Torus 26 I'll give few numbers describing my rec configuration which I believe will help discussion:
- TLS 350, 200 gr Thinsulate
- Pioneer 27
- alu backplate and 12 lbs of weight or steel backplate and 8 lbs of weight
- steel 12l tank roughly neutral when empty incl valve and reg
- some additional 2 lbs for canister

 

[dumpsterDiver]

If the diver is properly weighted for cold water single tank diving, i.e. eyelevel at the surface with no gas in their wing and a full cylinder then:

They have 100% of their wing's capacity to get their chin out of the water. That requires only a fraction of capacity of a 26, or 30 lbs wing.

The impacts of a buoyancy failure are pretty small as the diver is not relying on their wing to remain at the surface.

At the end of the dive the diver will be lighter by the weight of the gas they consumed, meaning they will be positively buoyant at the surface even when their wing is empty.

The diver needs enough wing to:

1) Float their rig when it is at it's most negative, when their cylinder is full. Sea conditions have little impact on this, if the rig is less than 26 lbs negative a 26 lbs wing will float it.

2) Have enough lift to compensate for the maximum possible change in buoyancy of their exposure suit.

If the diver is properly weighted and has not placed 100% of their ballast on their rig the buoyancy of the suit will dictate wing size.

Comfort at the surface is improved for the properly weighted diver, they need less gas in *ANY* size wing to get their chin out of the water.

Huge wings don't really help much to raise an over weighted diver out of the water, any portion of the wing that is above the surface offers no lift as it displaces no water. Big wings pretty quickly reach a point of diminishing returns.

Getting the weighting right, and the ballast distribution right pays far bigger returns than an over sized wing.

Far too often is see divers choosing a larger wing to solve an over weighting issue.

Tobin

What about the weight of the diver's head?

WikiAnswers - What is the weight of an adult human head

This reference says up to around 12 lbs and we know Jersey wreck divers have big heads.


I would assume that we would want to keep the entire head out of the water to allow reasonable access to breathing at the surface (without a snorkel, since so many people don't use them). What's a head weigh? Then you add in the effects of sea state and as previously mentioned, you definitely want some bouyancy when white caps are blowing over your head.

In addition, your assumption that the diver will ALWAYS have an empty tank at the surface is not necessarily applicable. I can imagine many scenarios where a diver would want to be able to comfortably float on the surface of a rough sea (especially NJ) and maybe wait for their buddy to get in, talk with people on the deck etc. There are many reasonas why a person may find some extra bouyancy very convienent, maybe it will not be life threatening to have very little excess bouyancy, but I know that I want the flexibility and security that some extra bouyancy provides when diving in rough conditions.

 

[dumpsterDiver]

....Most game is close to neutral, and the diver will be less negative by the weight of the gas they burned actually collecting the lobsters or shell fish. It's a damn big bag of scallops that is 6-7 lbs negative in the water.

Not really a good practice to use one's BC as a lift bag anyway........

Tobin

these comments show a true lack of understanding. Game is NOT neutral! Dead fish are normally quite bouyant unless their gas bladder is punctured. Scallops (like they get in the NE where this guy dives are very negative). I also know that a bag full of Florida lobsters can easily be 12 lbs negative.

As for the last statement: To imply that a hunter or game collector would not use his bouyancy compensator to compensate for game collected on a dive is really silly. Do you expect a diver to use a lift bag for most of the dive and to swim that around while collecting game and to then manage that bag on an ascent on an anchor line? Get real!

A lift bag represents a major pain in the butt and an expereinced diver would much rather use his BC to handle 10-12 lbs of negative weight from game or other treasures of the deep in his catch bag. Trying to manage a left bag to handle a game bag in strong currents, while diving from an anchored boat on a Jersey wreck would probably make the diver into "that guy". A lift bag is for anchors and extra weight belts which are often recovered.

It appears that you are really stretching things to try to justify a wing that is insufficent (based on my 35 yrs of real diving expereince).

 

[cool_hardware52]

What about the weight of the diver's head?

WikiAnswers - What is the weight of an adult human head

This reference says up to around 12 lbs and we know Jersey wreck divers have big heads.

I would assume that we would want to keep the entire head out of the water to allow reasonable access to breathing at the surface (without a snorkel, since so many people don't use them). What's a head weigh? Then you add in the effects of sea state and as previously mentioned, you definitely want some bouyancy when white caps are blowing over your head.

Humans eyes are about 1/2 way between the top and bottom of their head. My target for ideal weighting is

**EYELEVEL** with no gas in the wing and full cylinder. To get you chin out of the water would then require about 6 lbs.

6/26 = .23% of the capacity of a 26 lbs wing. 6/30 = 20 % of a 30 lbs wing. In other words a small fraction of the available lift capacity of either wing is required to get the divers chin out of the water.

This approach leaves 75% or more unused wing capacity to deal with all the tortured scenarios that have been offered in this thread, the "white caps" and full gear bags and buddies in distress etc. , etc.,

In addition, your assumption that the diver will ALWAYS have an empty tank at the surface is not necessarily applicable. I can imagine many scenarios where a diver would want to be able to comfortably float on the surface of a rough sea (especially NJ) and maybe wait for their buddy to get in, talk with people on the deck etc.

Please show me where I ever said a diver will always have an empty tank at the surface?? You have a reoccurring habit of putting words in peoples mouths.

A poster claimed one needs extra lift if they are bringing up game. If one is bringing up game it then follows that they actually went diving, you know like under the water, and used at least some of their gas.

Unless of course the game jumped into their bag while they were floating on the surface waiting for their buddy.

If the diver started the dive eyelevel at the surface with no gas in their wing and a full tank they will be positive by what ever gas they have consumed.

There are many reasonas why a person may find some extra bouyancy very convienent, maybe it will not be life threatening to have very little excess bouyancy, but I know that I want the flexibility and security that some extra bouyancy provides when diving in rough conditions.

If the diver is weighted as I suggest, eyelevel at the surface with no gas in their wing and a full cylinder, and has sized their wing to be able to float their rig and compensate for the maximum change in buoyancy of their exposure suit they already *HAVE* ample reserve wing capacity.

OTOH many divers are over weighted, and rely on an over sized wing / BC.

These are the divers who will be in real trouble if they suffer a buoyancy failure.

A failed wing may provide Zero lift.

Which is safer; Diver B, properly weighted so they can easily remain at the surface if their "as small as possible" wing fails,

or

Diver B 10 lbs over weighted, with a 40 lbs wing that normally floats him "high and dry", but today his inflator hose pulled off? As he struggles to stay at the surface I'm sure the "warm fuzzies" his extra large wing gave him will quickly fade.

In short divers need to understand weighting, and then select a wing that meets necessary criteria, pretty simple really.

A bigger wing is never the right solution to being over weighted, and a properly weighted diver can often use a wing much smaller than "conventional wisdom" dictates.

Tobin

 

[Scott L]

Why the snippy into to your response Tobin? :huh: I don't see anywhere in the OP's post where he was asking for YOUR advice. Just b/c he is diving your product doesn't mean he only wants your opinion. I would have thought the first line of the OP that says "hello all" would have made that clear.

To be fair, numerous posters subsequent to the OP were calling out to Tobin for guidance...

 

[dumpsterDiver]

Don't want to make this sound like an arguement, but I never suggested that a diver should be overweighted.

Also, I totally agree with you about your suggestion to wear a weight belt rather than having unditchable lead on the rig. Being able to ditch lead is something else I want to be able to rely on for added flexibility and security.

 

[Scott L]

If the diver is weighted as I suggest, eyelevel at the surface with no gas in their wing and a full cylinder, and has sized their wing to be able to float their rig and compensate for the maximum change in buoyancy of their exposure suit they already *HAVE* ample reserve wing capacity.

OTOH many divers are over weighted, and rely on an over sized wing / BC.

These are the divers who will be in real trouble if they suffer a buoyancy failure.

A failed wing may provide Zero lift.

Which is safer; Diver B, properly weighted so they can easily remain at the surface if their "as small as possible" wing fails,

or

Diver B 10 lbs over weighted, with a 40 lbs wing that normally floats him "high and dry", but today his inflator hose pulled off? As he struggles to stay at the surface I'm sure the "warm fuzzies" his extra large wing gave him will quickly fade.

In short divers need to understand weighting, and then select a wing that meets necessary criteria, pretty simple really.

A bigger wing is never the right solution to being over weighted, and a properly weighted diver can often use a wing much smaller than "conventional wisdom" dictates.

Tobin

I don't know Tobin, I ultimately yeild to your vast engineering & diving prowess but it does seem some margin for error with regard to weighting etc. would be realistic to assume in the real world...

 

[cool_hardware52]

Don't want to make this sound like an arguement, but I never suggested that a diver should be overweighted.

If the diver is properly weighted there is no need for a "extra large" wing.

If a cold water single tank diver is weighted so that they are:

Eye level at the surface with no gas in their wing and a full cylinder,

then if follows that they

1) Have 100% of the capacity of their wing available for comfort at the surface, as noted above one needs just a "puff" of gas to get one's chin out of the water, the balance of the wing capacity is effectively in reserve.

2) Will never be heavier, they don't gain mass as they dive, they will in fact loose mass as they breathe down their tank.


OTOH my experience is the over weighted diver is the one who places too much faith in big high lift BC's

Are there legitimate applications for wings with more than 26 lbs of lift? Of course, or DSS wouldn't produce or offer for sale 30's 35's and 40 lbs lift wings. Big people and or thick exposure suits need bigger wings.

Having said that the OP has not yet provided any information that leads me to believe that a 26 lbs wing is insufficient for his application, if he moves some of his ballast off his rig and onto a belt.

Tobin

 

[cool_hardware52]

I don't know Tobin, I ultimately yeild to your vast engineering & diving prowess but it seems some margin for error with regard to weighting etc. would be realistic to assume in the real world...

The method I use to determine wing sizing has quite a margin already built into it.

For example I want the wing to be able to compensate for the maximum possible change in buoyancy of the divers exposure suit.

In practice one can't fully compress a neoprene suit at recreational depths, you need to go to about 165 fsw to zero out neoprene, that builds in a little cushion.

To calculate the max negative buoyancy of the divers rig I use the buoyancy numbers for the cylinder, but just use the "dry weights" not the displacements for every thing else. This tends to under estimate the true maximum negative values for the rig, again this builds in a little cushion.

A high percentage of recreational diving injuries occur at the surface, or at least involve a diver who makes it to the surface alive, but is found later dead at depth.

Struggling and panic at the surface is a real problem. Proper weighting, which is unfortunately not often covered well in many BOW courses, is a key to this problem. The properly weighted diver should be not have to struggle to stay at the surface even if their BC fails or they are too panicked to use it properly.

The over weighted diver has to be proactive, drop weights, add gas to their BC etc. and that can be too much.

Proper weighting is a safety issue and is due much more attention than it now receives.

Tobin