Cold water Wing lift - again

[RJP]

Personally I would avoid the 40 pound wing if possible....just too big with more drag than you need, and the big air bubble moving around upsetting trim is bogus as well.

Yeah look at all that drag and poor trim...

PS - any given air bubble will be precisely the same size whether it's in a 30lb wing or a 40lb wing. (eg: a liter of air in a 30lb wing is still only a liter of air if it's in a 40lb wing)

 

[danvolker]

Yeah look at all that drag and poor trim...

PS - any given air bubble will be precisely the same size whether it's in a 30lb wing or a 40lb wing. (eg: a liter of air in a 30lb wing is still only a liter of air if it's in a 40lb wing)

Frog kicking is such a slow kick, that drag has far less impact on speed....although drag even for this is going to mean that a big kick, will not provide nearly as long of a big glide, as it would with the much lower drag of no wing at all.

As to bubble size, I see this as sort of like "work expands to the time allowed"....If the diver plans a 40 pound wing, chances are much better that they will end up USING the extra lift of the 40 pound wing, because they "can" support heavier tanks, wetsuits that lose more lift at depth, etc....which will translate into a larger bubble.

If the diver was using a 20 pound wing, they would need to make configuration and gear purchase choices, such as wetsuits with much less buoyancy loss at depth ( this limiting the thickness ) and potentially utilizing newer/better technology like the direction of the Heated Vest by Thermolution under the insulation of the 3 to 5mm wetsuit.

The wetsuit would be more effective, either the type for semi-dry, or ones that use the superior warmth characteristics of Freedive suits with Yamamoto rubber--where a 5 mil freedive suit is often warmer than the 8 mil scuba wetsuits( where the technology pushes the suits ability to have a diver crawl along the bottom on hands and knees like a goat-with great cut and tear resistance), over the need for warmth or optimal movement).

The diver buying the thick low tech wetsuit, will then figure they are fine buying a very heavy HP 100 ( or even heavier HP tank) , so when they get to 120 feet deep, the weight of the tank begins to really exaggerate the loss of lift from the thick suit....and the diver inflates the wing with this MASSIVE bubble to compensate....to compensate for something they should not be compensating for. THIS is the larger bubble I am referring to, from an entire series of wrong choices.


My point in this, is not that most divers should use an 18 pound lift wing like I do ( or no wing at all)....I think the 30 pound lift wing should provide all the lift most divers should need, if they purchase the correct wetsuit and use the correct tanks.

When you get to water too cold for the 3 to 5 mm higher tech wetsuits ( aided by heated vests), then you are in dry suit territory--which still means you can use a 30 pound lift wing.

---------- Post added October 18th, 2015 at 08:12 AM ----------

An example of what "could be" :

Consider a place where a diver might live( or do most of their diving in), where the principal dive sites they enjoy are reefs or wrecks with a known and average bottom depth they will stay close to for most dives.... In such a place ( like Palm Beach, or Catalina in the Kelp (or a hundred other sites) consider a reef line the diver will always be following, with a known depth of say--60 feet deep. It is quite easy for the diver to determine the exact weighting they need with their high tech wetsuit, to be dead neutral at 60 feet, with no wing or bc on....So while in jumping in, they may need to swim downward a bit harder the first 20 feet--like freedivers do....this effort quickly disappears and on reaching their cruising depth, not only is the diver neutral, they are at a much lower drag, which makes their efficiency in propulsion far better, and gas consumption much lower than would occur for their "evil twin" with the traditional scuba setup.


This translates to frog kick where a big kick can create a 10 foot long glide, and actually have the wing-less but neutral diver swimming with frog kick at the speeds of other divers utilizing their flutter kick at full cruising power....or, if the wing-less diver wants to cross over a 400 foot long section of empty sand between 2 reef systems, he can switch to dolphin kick and reach the next reef in 1/3 of the time the traditionally geared divers would require, with 1/3 or less of their gas consumption in this traverse.

Again, I am not suggesting this as any kind of immediate behavior for SB members....If some like this, the first step would be switching to 18 pound wings, and gearing so that when they are a their normal bottom depth, they need ZERO gas added to their BC....and on ascent, and safety stop, so what if they need to keep their feet up over their heads and maintain a steady but easy downward swimming force, to hold 20 feet deep at the stop.....

If they want EXTREME COMFORT on the surface, they can have a snorkel they keep in a storage pouch on the backplate, that they pull out during the safety stop, attach to their mask strap while they are doing nothing during this several minutes...and then they will be perfection on the surface, when they come up. There are many ways of dealing with where to keep a snorkel during a dive. I would much rather deal with the snorkel, than with a BC or wing!

 

[RJP]

As to bubble size, I see this as sort of like "work expands to the time allowed"....If the diver plans a 40 pound wing, chances are much better that they will end up USING the extra lift of the 40 pound wing, because they "can" support heavier tanks, wetsuits that lose more lift at depth, etc....which will translate into a larger bubble.

If the diver was using a 20 pound wing, they would need to make configuration and gear purchase choices, such as wetsuits with much less buoyancy loss at depth ( this limiting the thickness ) and potentially utilizing newer/better technology like the direction of the Heated Vest by Thermolution under the insulation of the 3 to 5mm wetsuit.

So you're suggesting that divers should blindly buy a small wing and then be forced to configure (compromise?) the rest of their gear around that wing choice?

 

[halocline]

My simple math says that you need a 40b wing at a BARE Minimum. -20 of weight, -12 full cylinder, -8 to keep your head above water. I'm not sure about that weight calculator, but 40 seems quite a bit more logical than 22 with your configuration.

This is complete nonsense. The required lift is based on two things; 1. Compensating for the loss of buoyancy of your wetsuit through compression plus the weight of the gas, and 2. Whatever is needed to float the rig at the surface. Nobody would ever be close to 40 lbs negative at the surface in a single tank. The 20 lbs in weight is there to offset the surface buoyancy of the wetsuit.

Since you work at a dive shop and are presumably posting on its behalf, try to research your basic dive information before posting. It's not great for the credibility of your shop. I'm sorry to have refuted your posts a few times now, but it's annoying when a dive shop salesman posts clearly wrong information. Many of us on SB like this site specifically because it's an alternative to the dive shop BS we've all been fed before.

Getting back to the OP, there's almost no situation I can think of in which 30 lbs is not sufficient lift for single tank diving. I guess if you had ALL your ballast on the rig, you'd need a larger-than-normal wing to float it. 40 lbs is a pretty big wing, but there might be some designs that are fairly streamlined and easy to vent. Just avoid big wings with wide centers.

As far as how much weight (lead) you'll need when you switch to a BP/W, you'll just have to do a weight check, but you can start with 8 lbs less and go from there. That's counting 6lbs negative for the steel plate and assuming your current BC is 2 lbs positive; it might be more.

---------- Post added October 18th, 2015 at 08:40 AM ----------

But I still will keep most of that weight on a belt - in that case, wouldn't the wing lift be independent of the lead weight?

Yes, you are correct.

---------- Post added October 18th, 2015 at 08:42 AM ----------

Yeah look at all that drag and poor trim...

PS - any given air bubble will be precisely the same size whether it's in a 30lb wing or a 40lb wing. (eg: a liter of air in a 30lb wing is still only a liter of air if it's in a 40lb wing)

It looks like you had fish for lunch.....

 

[danvolker]

So you're suggesting that divers should blindly buy a small wing and then be forced to configure (compromise?) the rest of their gear around that wing choice?

No...I think they should borrow, demo, or rent a 30 pound wing( rent w/option to buy), to try what I suggested. I am Not a fan of shops that won't rent or demo key gear that is potentially very key to the diver's enjoyment of diving.

With the right wing, the diver will not "COMPROMISE" all their future diving, by purchasing the WRONG tanks and WRONG Wetsuits

Many Dive Shops love to sell stupidly heavy tanks. That may play ok for Dry suit divers.....and in some cold water locations they may mount a reasonable argument in favor of their heavy tank choices....But this is not the ONLY way to deal with cold water and it's implications. In a real sense, a cold water shop, selling a local diver a stupidly heavy tank, creates an addict of sorts....it causes a whole cascade of "high buoyancy need" choices, which will push this diver to end up slower, working harder to move...causing a diver to feel they need even bigger tanks in the future, and perhaps even needing bigger bc's and even thicker and more buoyant wetsuits. At some point, this evolves the diver up to the point that it is quite apparent that the Dry Suit is the only way to go....Then several grand for a Dry suit purchase, some profit on a course to learn diving in a dry suit....then potentially a different wing or BC for the Drysuit to be more optimal for it...and maybe even a different kind of tank....Of course, this diver has so much drag now, that swimming anything but very slow, is too much work...so now the shop can sell the diver a scooter from 4 thousand to 6 thousand dollars, and then the diver can cover plenty of ground on each dive again

Then, after the diver goes as far as this will go in purchases, the shop has them evolved to the point at which they will be receptive to purchasing a Rebreather.


I think my plan is the better one, for an athletic and well coordinated type of diver.

---------- Post added October 18th, 2015 at 09:59 AM ----------

---------- Post added October 18th, 2015 at 08:42 AM ----------



It looks like you had fish for lunch.....

The picture does look a bit like the Warhammer Maneuver

 

[dumpsterDiver]

A larger capacity wing makes a diver "strong" and capable. It allows them the capability to catch a bunch of heavy lobsters and still float along in a neutral condition. It allows them the ability to find an 18 lb weight belt on the bottom, put it on, continue the dive .. and then sell the whole thing on ScubaBoard a few weeks later.
http://www.scubaboard.com/forums/cl...tems/509578-soft-lead-bags-various-sizes.html.

A larger capacity BC allows a diver to be able to drag an overweighted diver with failed gear to the surface with less effort. A larger capacity BC allows a diver to better support a struggling diver at the surface. A larger capacity BC will allow the diver to float higher at the surface and be better able to see the dive boat (or an oncoming one).

A larger capacity BC will allow the diver to safely dive a thicker suit or an additional layer of suit, when the water is unusually cold.

I'm currently using a 44 lb wing for warm water and it is actually bigger than I would prefer. I think something around 35 lbs might be better for me. The disadvantages of 10 lbs of excess volume capacity should not be exaggerated. If I dove a 7 mm full wetsuit all the time, I would NOT want a 30-lb wing..

 

[Storker]

Personally I would avoid the 40 pound wing if possible....just too big with more drag than you need, and the big air bubble moving around upsetting trim is bogus as well.

I dive a 40# wing, a DS with heavy undergarments and a steel single. I've done the math, and it clearly showed that 40# is necessary to float my rig if I doff it in the water. Underwater, the wing is practically empty most of the time, so this "big air bubble" "with more drag than you need" and "moving around upsetting trim" is a pretty moot point.

In my real life diving, I've had my math confirmed. I need that kind of wing capacity, because even with a full wing and getting on my back on top of the bladder, I'm not floating particularly high above the water.

 

[danvolker]

A larger capacity wing makes a diver "strong" and capable. It allows them the capability to catch a bunch of heavy lobsters and still float along in a neutral condition. It allows them the ability to find an 18 lb weight belt on the bottom, put it on, continue the dive .. and then sell the whole thing on ScubaBoard a few weeks later.
http://www.scubaboard.com/forums/cl...tems/509578-soft-lead-bags-various-sizes.html.

A larger capacity BC allows a diver to be able to drag an overweighted diver with failed gear to the surface with less effort. A larger capacity BC allows a diver to better support a struggling diver at the surface. A larger capacity BC will allow the diver to float higher at the surface and be better able to see the dive boat (or an oncoming one).

A larger capacity BC will allow the diver to safely dive a thicker suit or an additional layer of suit, when the water is unusually cold.

I'm currently using a 44 lb wing for warm water and it is actually bigger than I would prefer. I think something around 35 lbs might be better for me. The disadvantages of 10 lbs of excess volume capacity should not be exaggerated. If I dove a 7 mm full wetsuit all the time, I would NOT want a 30-lb wing..

I get that some divers want to carry huge loads on some dives.....each of us has a right to the "MISSION" we enjoy most...

There are some, like DD, that may be more like this:


And some divers may be more like this...where the mission is to cover more ground, to explore, and to be able to really move when needed...

 

[Diving Dubai]

I dive a 40# wing, a DS with heavy undergarments and a steel single. I've done the math, and it clearly showed that 40# is necessary to float my rig if I doff it in the water. Underwater, the wing is practically empty most of the time, so this "big air bubble" "with more drag than you need" and "moving around upsetting trim" is a pretty moot point.

In my real life diving, I've had my math confirmed. I need that kind of wing capacity, because even with a full wing and getting on my back on top of the bladder, I'm not floating particularly high above the water.

Couldn't agree more!

I dive a 15l steel and a S50 as a redundant. in the summer my exposure protection (sharkskin 1 piece) is neutral. Again I've tried a 30lb and like Storker I float too low at the surface. My 36 (Dive Rite Voyager) is perfect I can lie back and hang out all day in comfort.

I'm not getting into the streamlining discussion. If I really could be bothered I'd get a fluid dynamics model knocked up to prove the fallacy of a load of statements o diver drag- unfortunately I'm too busy picking my nose and scratching my arse to have the time or inclination to do that

 

[dumpsterDiver]

I get that some divers want to carry huge loads on some dives.....each of us has a right to the "MISSION" we enjoy most...

There are some, like DD, that may be more like this:
View attachment 218181

And some divers may be more like this...where the mission is to cover more ground, to explore, and to be able to really move when needed...
View attachment 218182

when the leaping guy's foot hits the moss covered rock, he is going WISH he was wearing a pack and padding in front as well..