Wing Size Suggestions...

[b1gcountry]

In short, with 16 lbs of back gas and a suit that is ~28 lbs positive a 40 lbs wing is too small.

I think you misunderstood my point a little. My 40lb wing works pretty well with this setup when I'm diving, and it vents like a charm, but it doesn't float my rig on the surface...which is something I never have to do on the boats around here anyway.

The 55lb wing I have will float the rig on the surface, but it really is floppy in the water, and doesn't vent as well as my 40lb wing. In fact, I can never really get that last bit of air out without using the corrugated hose, and it is not a technique issue.

A lot of times I just wind up using the 40lb wing because it is so much nicer in the water. I was just asking what risks was I really exposing myself to that while diving this way. TS&M said it's not good when you have to doff your gear to enter the boat. I suppose it's also a slight risk if my drysuit ever gets completely flooded, but I don't consider that a realistic scenario. Anything else I'm not thinking about?

Tom

 

[cool_hardware52]

I think you misunderstood my point a little. My 40lb wing works pretty well with this setup when I'm diving, and it vents like a charm, but it doesn't float my rig on the surface...which is something I never have to do on the boats around here anyway.

I'm pretty sure I understood it. Your current configuration fails in both respects, you can't float your rig, and you can't deal with a total drysuit failure, but you are willing to defend these choices.

The 55lb wing I have will float the rig on the surface, but it really is floppy in the water, and doesn't vent as well as my 40lb wing. In fact, I can never really get that last bit of air out without using the corrugated hose, and it is not a technique issue.

There are wings made today of greater than 40 lbs of lift that can be fully vented.

A lot of times I just wind up using the 40lb wing because it is so much nicer in the water. I was just asking what risks was I really exposing myself to that while diving this way. TS&M said it's not good when you have to doff your gear to enter the boat. I suppose it's also a slight risk if my drysuit ever gets completely flooded, but I don't consider that a realistic scenario. Anything else I'm not thinking about?

Tom

I stand by my statement

If the rig is the controlling factor something is usually amiss, and the diver is over weighted.

In your case what is "amiss" is you are using too small a wing. I'm a big believer in using the smallest wing that safely meets the needs of the diver, but your current configuration calls for either a larger wing or redeployment of your ballast.

I just wind up using the 40lb wing because it is so much nicer in the water.

I'd prefer to ride my mountain bike without a helmet, it's much "Nicer" too.........

Total failure of a drysuit is an uncommon event, but still possible. As currently configured you can neither float your rig, or ditch any ballast.

With my 400g thinsulate, diving in fresh water, I only take 4lbs, which I usually stash in my undergarment pockets.

If you switched to a lighter backplate (6 lbs vs 10 lbs) and used a belt for the 4 lbs you now place INSIDE your suit, you'd end up with a 8 lbs weight belt. That would allow you to both float your rig, and deal with the effects of a total suit failure.

My first choice would be a larger wing, as dropping ballast makes a controlled ascent much less likely.

If the dive goes as planned and you use the wing only to compensate for the change in weight of your backgas the 40 will seem like a reasonable choice, but the day things don't go as planned is when you may find the weakness of your gear selection.

To promote such inappropriate use on a public forum is a disservice to the less well informed WHO MAY NOT UNDERSTAND the risks they would be taking.

Tobin

 

[MonkSeal]

To be honest I don't see much sense in taking weights inside dry suit.

 

[b1gcountry]

Tobin-
First off, I was asking the question to learn what possible dangers might be involved, I was not proscribing anything, I was asking the question myself. See my post #3 if you missed it.

Second, even when I'm wearing an aluminum plate, my rig will not float in fresh water with full tanks. It will float it once I get to around half a tank though. So even switching to an AL backplate doesn't really solve my problem all the way. I bought a 55lb Halcyon earlier this year, which I figured would fix the problem, and it does, although I just don't like using it as much. It wraps around the tanks a lot, and the last little bit of air gets trapped in the corner of the wing just above the dump valve.

My question was how much of a risk am I really taking by diving with the 40# wing?

It doesn't affect me much not being able to float the rig on the surface since that is something that I would never see myself as having to do. The boats I dive off of always have good ladders, so doffing my gear is never part of the plan for me. If I were ever in the situation where I had to be taken out of the water in an emergency, I consider my gear acceptable losses. Is there a situation you have in mind where you see a danger that I'm missing?

Anytime I'm diving doubles, I'm in Lake Michigan. Having a suit flood of any kind is something I very much try to avoid, but it's happened a couple times. I've never had so dramatic of a suit flood where I lose all buoyancy. If my suit is 28lbs buoyant. I would probably have to lose 20-24lbs of buoyancy from the suit for it to become a problem. It that really possible? Has anything like this ever happened to anyone before?

Tom

BTW, I moved all my weight to my weight belt bc I was trying to get the weight off my rig so it would float. I didn't care for having the weight belt, and I was a little concerned about losing it, so I tried sticking it inside my suit instead, and I kind of liked it.

 

[cool_hardware52]

Tobin-
First off, I was asking the question to learn what possible dangers might be involved, I was not proscribing anything, I was asking the question myself. See my post #3 if you missed it.

I've detailed the risks, and you apparently you are not concerned about being able to float your rig should you need to ditch it, or return the surface in the event of a total failure of your dry suit.

Second, even when I'm wearing an aluminum plate, my rig will not float in fresh water with full tanks.

You have detailed in a previous post that your rig is ~40 lbs negative with a 10 lbs back plate.

16 lbs air
8 lbs tanks, manifold, bands
4 lbs regs
10 lbs plate
2 lbs can light

So my rig is around 40 lbs negative,

Now you state that even with an al plate, which will be about 8 lbs less negative that a 40 lbs wing still won't float your rig.

How do you explain this?

It will float it once I get to around half a tank though. So even switching to an AL backplate doesn't really solve my problem all the way.

This implies your rig, with an al plate is about 48 lbs negative (half your gas = 8 lbs)

This also implies that your rig with the SS 10 lbs plate is about 56 lbs negative!!

In short your numbers make no sense. Have your verified the actual lift your wing provides?

Tobin

 

[Rainer]

Is there a situation you have in mind where you see a danger that I'm missing?

Flooded dry suit (complete flood). Do you assume it can't happen?

 

[kidsdream]

In addition to Tobin's great products the Vertex 55lb is very nice option for 3442PSI 100's. While rated specified at 55lb a study showed that they are effectively provide around 48 lift when sandwiched to a BP.

I haven't tried that many doubles wings, but I could not be happier with this setup.

 

[divingbuddy]

I see that own size/equipment configurations factors significantly in determining how much lift I safely require, and thus which wing would be best...

I am 5'6" and weigh 160 pounds. I am fairly muscular, with a relatively low body fat percentage. Diving in the pool with a shorty or skin I don't need a weight belt when diving with an AL80 and stab jacket. I am a sinker.

I dive double HP 100s with a 6 lb SS BP and hog harness.

I require no additional weight. In fact, I descend quite nicely when I vent the air from my wing.

I like the design/shape of the Evolve wing, and it is an item that my LDS sells (which I would like to continue to support).

I would like to purchase the wing that best suits my needs, without being too big or 'floppy', as I have found in the past using other wings. I do plan to continue on after fundies towards Tec 1 (and hopefully Cave 1 too), so I do need to consider the additional buoyancy requirements of stages, etc.

Should I consider the AL plate instead of the SS one I currently use?

Any further assistance would be greatly appreciated. Cheers!

 

[b1gcountry]

Should I consider the AL plate instead of the SS one I currently use?

Probably, but depends on the undergarment. I wear 4 lbs with a stab jacket in a pool, and an AL BP is just about right for me with my HP100s, and TLS 350 with light Fleece Underwear in freshwater. Sound like you are heavier than me in the water, and wearing more ballast. See how fast you sink with a near empty tank, and that will tell you for sure.

Tom

 

[cool_hardware52]

I see that own size/equipment configurations factors significantly in determining how much lift I safely require, and thus which wing would be best...

I am 5'6" and weigh 160 pounds. I am fairly muscular, with a relatively low body fat percentage. Diving in the pool with a shorty or skin I don't need a weight belt when diving with an AL80 and stab jacket. I am a sinker.

Your "personal buoyancy" will impact your total weighting, but it does not impact required lift. Buoyancy Compensators are used to compensate for things that change in buoyancy during the dive. Your "personal buoyancy" won't change.

I dive double HP 100s with a 6 lb SS BP and hog harness.

I require no additional weight. In fact, I descend quite nicely when I vent the air from my wing.

That really tells me nothing. Given that in doubles you should be starting the dive negative by the weight of your backgas + ~2-3 lbs. You should of course be ale to descend when you vent your wing.

The goal is to have your total ballast, with empty tanks = the minimum buoyancy of your drysuit + 2-3 lbs.

If you know the actual buoyancy of your Drysuit with minimum gas, gear choices become pretty simple to make.

To test your suit put on your undies and drysuit and grab a big bag 'o' lead. Find some neck deep water. Jump and vent all the gas you can from your suit. Remove lead until you are just neutral. Weigh the bag 'o' lead.

If you are truly negative in your swim trunks add about 2 lbs to the measured value.

Lets say you find your suit, with minimum gas is requires 16 lbs to get neutral.

With 2 x 100's you have 16 lbs of gas. Suit (16) + gas (16) + 2 lbs = 34 lbs.

Rig:

2 x 100' empty -3 (depending on maker)
Bands and manifold -4
Dual regs -4
Can Light -2
Lightweight Plate & harness -2

Total -15

You would need a couple more lbs to reach the ~17-18 lbs negative that is the target. Soft weight pouches between the wing and plate is an easy way to add small additional amounts of ballast to doubles rig.

Your rig would be about 18 +16 (gas) = 34 lbs. It's not chance that this value, 34 equals the buoyancy of your suit + your gas + ~2 lbs from above.


Remember this example is based on MY ASSUMPTIONs about a hypothetical configuration, you should test your own suit.

It should be clear that the major player in both weighting and wing sizing is the buoyancy of your exposure suit. Without this information everything is a guess.

Tobin