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When i went onto twinset diving, I thought long and hard about which wing to go for. I am aware that a significant number of incidents happen in relation to the difficulty in establishing postive buoyancy at the surface and took this into account when making my decision. I acted on advice and bought a dual bladder wing (Diverite Superwing 2). I have to say that i really liked it.

I went off to the dive show, and found the Frog Bargain. i had read about my drysuit supposedly providing redundant buoyancy, so i should be OK with a single bladder wing. Other advice was that a single bladder wing was the right thing to have. For me, the cost was worth 'giving it a go'.

I got the wing in February, i think it was and dived with it on several occasions. Nothing special, but no complaints either. Then I went to Swanage. I sat out of one of the boat dives, to accompany a nervous diver under the pier. He had had a bad experience on the Kyarra that morning, and needed a bit of confidence building. I wouldn't normally do a 4m dive with the twins, but hey ho, in for a penny!

We got in, swam out to the start of the pier and descended. Within a minute or so, I lost him (yes, the viz was that bad!) and surfaced (he was there!). I tried to fill the wing, ony to find that my low pressure inflator stuck open and was fizzing air out all over the place, and I couldn't get buoyant. I have no idea why, but i couldn't orally inflate the wing either at that point. No problem, i thought... shove air into the dry suit - that'll keep you afloat. I shoved air in but before I could relax and stop finning, the neck seal vented - Drysuit full.

OK,.... I am in about 4m of water under Swanage pier, and I can't stay afloat. Marvellous (but not really life threatening). So we descended again and remained under to navigate our way back to a position where i could stand, problem over. Luckily, i had shedloads of air and i was in shallow water. If the wing had failed that morning, I would have been in 30m of water and not so easy a situation to resolve.

I learned that day that my drysuit is not sufficient redundant buoyancy for a 12l twinset, SS backplate and no other kit in a situation where my wing fails.

I had the inflator looked at, and it is perfectly fine now- an o ring had failed. However, i won't dive with that wing again - back to the dual bladder Diverite.:)
 

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nEw MeMbEr
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waving

You don't go on to mention that same weekend that you were talking on your mobile to a friend on the pier whilst you whilst you ate & drank at the tea stall. Waving to identify yourself.

Everyone else sitting there was waving to her too
(Nice work.)

Put a string on your tailgate yet?

Nice to meet you

s
 

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A short fat well off crap cave diver. Likes wrecks
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When i went onto twinset diving, I thought long and hard about which wing to go for. I am aware that a significant number of incidents happen in relation to the difficulty in establishing postive buoyancy at the surface and took this into account when making my decision. I acted on advice and bought a dual bladder wing (Diverite Superwing 2). I have to say that i really liked it.

I went off to the dive show, and found the Frog Bargain. i had read about my drysuit supposedly providing redundant buoyancy, so i should be OK with a single bladder wing. Other advice was that a single bladder wing was the right thing to have. For me, the cost was worth 'giving it a go'.

I got the wing in February, i think it was and dived with it on several occasions. Nothing special, but no complaints either. Then I went to Swanage. I sat out of one of the boat dives, to accompany a nervous diver under the pier. He had had a bad experience on the Kyarra that morning, and needed a bit of confidence building. I wouldn't normally do a 4m dive with the twins, but hey ho, in for a penny!

We got in, swam out to the start of the pier and descended. Within a minute or so, I lost him (yes, the viz was that bad!) and surfaced (he was there!). I tried to fill the wing, ony to find that my low pressure inflator stuck open and was fizzing air out all over the place, and I couldn't get buoyant. I have no idea why, but i couldn't orally inflate the wing either at that point. No problem, i thought... shove air into the dry suit - that'll keep you afloat. I shoved air in but before I could relax and stop finning, the neck seal vented - Drysuit full.

OK,.... I am in about 4m of water under Swanage pier, and I can't stay afloat. Marvellous (but not really life threatening). So we descended again and remained under to navigate our way back to a position where i could stand, problem over. Luckily, i had shedloads of air and i was in shallow water. If the wing had failed that morning, I would have been in 30m of water and not so easy a situation to resolve.

I learned that day that my drysuit is not sufficient redundant buoyancy for a 12l twinset, SS backplate and no other kit in a situation where my wing fails.

I had the inflator looked at, and it is perfectly fine now- an o ring had failed. However, i won't dive with that wing again - back to the dual bladder Diverite.:)


Good ish point, but your going to take some flack for it.

With just a twin set there is no way you should have had a problem using your dry suit for buoyancy control. What your admitting to is being overweighted in the first place.

The suit should theoretically only be compensating for the weight of gas in your cylinders.

However a dry suit is not supposed to lift you head and shoulders out of the water like a big wing can. If thats what you were expecting the fair point the duel bladder wing is definitely a plus.

My view is, if your diving multi tanks in a wet suit then a duel wing is a must have. The usual reasons put forward to not to have a duel wing are rubbish.

ATB

Mark Chase
 

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Discussion Starter · #4 ·
You don't go on to mention that same weekend that you were talking on your mobile to a friend on the pier whilst you whilst you ate & drank at the tea stall. Waving to identify yourself.

Everyone else sitting there was waving to her too
(Nice work.)

Put a string on your tailgate yet?

Nice to meet you

s
Oh, that was sooooooo funny!

Nice to meet you too!

Good ish point, but your going to take some flack for it.

With just a twin set there is no way you should have had a problem using your dry suit for buoyancy control. What your admitting to is being overweighted in the first place.

The suit should theoretically only be compensating for the weight of gas in your cylinders.
'Taking flack' for it isn't really the purpose of the thread, or this sub forum. This area is supposed to be to pass on incidents which taught us something about diving. This taught me that I don't want to use a single bladder wing.

Maybe, I was overweighted at that point. I had 4kg, which is what i need to hold a 6m stop at the end of a dive with diddly squat air in my tanks. TBH, if I had thought about it, I didn't need that much, because I had about 100 bar in the twins ad could probably have left some behind. However, the considerations when you are about to do a 4m dive are very different to when you are about to do a 40m dive. I could have taken a couple of kilos off the harness but didn't. Don't we all start a dive overweighted, to compensate for the air you will use?
 

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His Holeyness
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. . . 'Taking flack' for it isn't really the purpose of the thread, or this sub forum. This area is supposed to be to pass on incidents which taught us something about diving.
Shame it's not taught you to check your equipment before you get into the water :rolleyes:



ColinM
 

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Discussion Starter · #6 ·
Shame it's not taught you to check your equipment before you get into the water :rolleyes:



ColinM
Did I say I hadn't? Nope. I have no idea when the thing failed. I swam out to the entry point - with air in the wing. It didn't get in there by magic. :D
 

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Unfortunately, I tend to agree from Mark. You didn;'t learn that drysuit is insufficient buoyancy for a a twinset - it should be more than ample.

We regularly practice failed wing ascents using the drysuit. Apart from being more difficult to hold stops (though not being as familiar with the practice) it should be no real drama.

The tendancy to overweight can be tempting, but it just causes so many problems, and exposes you to risks, that it's really not worth it.

What leassons can be learnt from this -

1. Overweighting can cause small problems to evolve into large problems,
2. Weight checks should be done often.
3. We should, IMHO, be correctly weighted with virtually empty cylinders. Not 30 bar. Not 50 bar. But next to nothing. If we are having to breathe our cylinders down to nothing because of a problem, the last thing we want is to lose control of buoyancy then as well. If you do your weight checks with 50 bar, then you might as well consider the last 50 bar unbreatheable.
 

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Discussion Starter · #8 ·
Unfortunately, I tend to agree from Mark. What you learnt was not that a drysuit is insufficient buoyancy for a a twinset - it should be more than ample.

What you learnt is that if you are overweighted, which it sounds like you almost certainly were, a drysuit may then be insufficent redundant buoyancy.

We regularly practice failed wing ascents using the drysuit. Apart from being more difficult to hold stops (though not being as familiar with the practice) it should be no real drama.
Yep, It should be. However, in this case it wasn't. I have done weight check after weight check and still come up with the same result. If i want to be able to hold a stop with near empty tanks, i need 2kg in fresh, therefore, in theory, 4kg in salt.
 

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Well I use 4Kg with twin 12s and I would not say I am overweighted. I am weighted so that I can holf a stop at 3m with 50bar. That should equate to holding a stop slightly deeper with slightly less gas. I virtually always end up completeing the final stops with nothing in the wing so am struggling to see what the issue with that might be.

I have a dual bladder wing having bought it for an exped diving 50m to 60m in a 3mm wetsuit. Maybe it is not optimal for UK diving but it is perfectly adequate. In the UK the additional inflator is stowed disconnected out the way but could be crosspatched from my DS inflate with a bit of effort. Personally I think having it connected permanently could cause more problems than it might solve (weeping inflate hoses, inadvertantly hitting the inflate while doing something else). In the situation of a failed wing and struggling for surface buoyancy I can dump the 4KGs, dump stages, inflate a lift bag or DSMB and dump the set if needs be.

YMMV
 

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Those who point out that to be correctly weighted we need to be neutral when our tanks are nearing empty are of course correct.

However, staying down is only one part of the equation. We also have to consider any loss of buoyancy during the dive (from compression of neoprene in our suits etc. when we are at depth) If we lose our main source of buoyancy (a wing failure) at the start of a dive we may still have a full gas load (and perhaps the burden of a compressed suit which took lead to sink it at the start of the dive but now provides less lift until we can return to the shallows). We need to be able to get up again.

It is not enough to say that a drysuit will act as redundant buoyancy. It depends on the sort of suit, the undergarments chosen etc. With my regular kit in Florida, no added weight and a fully inflated 60lb wing I can barely get my head out of the water on the surface - a change of kit configuration sorted this out. Remember it is total weight v total buoyancy - both must be balanced.

A suit should be able to handle the weight of the gas in twin 12s though - I've done it a few times to check and it is managable, although slightly unpleasant if you are not used to it. A large amount of gas in a drysuit is very unstable - and has to be managed carefully as the bubble will move to the highest point. Going vertical will allow gas to burp out of the neck seal as one board member on this thread found. If a large amount of lift is required in an emergency it is best to look at moving some of the weight to a form which is ditchable in such circumstances.

So - double bladders. You already have two sources of buoyancy to manage - your suit and your wing - and two inflators that could fail. Most who choose to dive a second bladder on their wing do not dive it connected as this would add a third potential failure - but prepare to connect it in case of problem. I see no need for this in a carefully weighted kit set up - especially with a drysuit - but your own view may differ.
 

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Hi Scubee,

if you don't want to dive a single bladder anymore I wouldn't presume to try and change your mind, live and let live I say :)

I have a single bladder, but use my suit for buoyancy [even with a stage] so I suspect I'd only notice a problem at the surface.

Glad it happened in a non critical depth and location.

Safe diving,
Steve
 

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My view is, if your diving multi tanks in a wet suit then a duel wing is a must have. The usual reasons put forward to not to have a duel wing are rubbish.
Mark,

Whilst I usually have a great degree of respect for what you post I don't necessarily agree with you in this instance.

Question: What are the millions of divers using "normal" BCDs doing when their BCDs "blow up"?

Answer: They don't blow up.

Comment: A Wing "BCD" is even less likely to blow up, given that the diver/owner has had the intelligence to buy one in the first instance.

When I use my semidry (usually the case in my waters) I have no requirement for weights if I'm in (steel) twin tank mode. Speaking entirely personally I don't consider that a problem.

Yes, I know that I can swim up in that configuration if I have to and, yes, in my case the dive boat is always anchored and I, but always, ascend via that anchor line.

Those two are the major differences to what you are used to in the UK. Sometimes it's worth pointing out that there are differences in diving.

Cheers,

Christian
 

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Umm, bitova problem here?

My view is, if your diving multi tanks in a wet suit then a duel wing is a must have. The usual reasons put forward to not to have a duel wing are rubbish.
Mark,

Whilst I usually have a great degree of respect for what you say I don't necessarily agree with you in this instance.

Question: What are the millions of divers using "normal" BCDs doing when their BCDs "blow up"? They don't have the benefit of a "twin wing", indeed they probably don't even know what a "wing" (apart from as in an aircraft) is (the newbies will almost certainly be overweighted).

Answer: They don't blow up. Even the rental ones that the newbies are likely (hopefully in fact AFAIAC) to be wearing.

Comment: A Wing "BCD" is even less likely to blow up, given that the diver/owner has had the intelligence to buy one in the first instance.

When I use my semidry (usually the case in my waters) I have no requirement for weights if I'm in (steel) twin tank mode. Speaking entirely personally I don't consider that a problem. Yes, I know that I can swim up z(been there, tested it out) in that configuration if I have to and, yes, in my case the dive boat is always anchored and I, but always, ascend via that anchor line.

Those two are the major differences to what you are used to in the UK. Sometimes it's worth pointing out that there are differences in diving.

Cheers,

Christian
 

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Resident 'Jawling Man' and 'Graunching Specialist'
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BCDs and Wings DO fail - hoses come adrift from their fixings or tear, simialrly inflators can fail to inflate or simply fail to hold air at all, dump valves can jam open or fail, the inner lining of some bcds can perish and fall apart or be damaged by large salt crystals. I for one am a firm believer in redundant buoyancy be that a drysuit, a seond bladder when wet suit diving. Some divers consider a lift bag to be a sufficient redundant buoyancy source but I would not.
 

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A short fat well off crap cave diver. Likes wrecks
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Mark,

Whilst I usually have a great degree of respect for what you post I don't necessarily agree with you in this instance.

Question: What are the millions of divers using "normal" BCDs doing when their BCDs "blow up"?

Answer: They don't blow up.

Did you read the post i am talking about multi tank deep dives involving decompresion commitment. Single tank rigs can be finned up and weight belts droped. Deco divers dont have the option to fin up or drop weight belts.

Comment: A Wing "BCD" is even less likely to blow up, given that the diver/owner has had the intelligence to buy one in the first instance.

In 2003 at a depth of 100m outside the blue hole in Dahab a diver pulled the inflater straight off his wing type bcd. He sunk to 120odd m before Jo Davin (TDI Instructor) managed to catch him and lift him back to his first deco stop.

In 2004 my friend Pete had his elbow to the inflater hose snap off because the plastic had perished. Fortunately it happened during cleaning

In 2006 Clare Gledhall pulled the inflater off her Halcyon wing in Vobster

In 2006 Burney decended to 65m and then hit the inflate button on his BCD. It failed no gas got through to the wing. He had to pull his twin 18s of air back up the shot.

In May 2007 anther DIR diver pulled the inflater hose off the Halcyon wing and his report on DIRX lead to others reporting similar problems. Halcyon have apparently redesigned the elbow and some retailers have done modification to prevent it occurring but there are still a lot of wings out there unmodified.

And these are just the cases i know about.

When I use my semidry (usually the case in my waters) I have no requirement for weights if I'm in (steel) twin tank mode. Speaking entirely personally I don't consider that a problem.

Yes, I know that I can swim up in that configuration if I have to and, yes, in my case the dive boat is always anchored and I, but always, ascend via that anchor line.

Those two are the major differences to what you are used to in the UK. Sometimes it's worth pointing out that there are differences in diving.

Cheers,

Christian

Sure if you have the option of an anchor line ascent then its doable but I have done plenty of wet suit diving in the red sea with no anchor line ascents. My two deepest dives in the Red Sea on CCR were 91 and 105m both were free ascents.

When I dived with Poseidon Divers in Dahab you were not allowed to do technical diving depths without a double bladder wing or a wing and a dry suit.

This rule was apparently the result of two incidents where buoyancy was lost over 1000+m of water.

ATB

Mark Chase
 

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Did you read the post i am talking about multi tank deep dives involving decompresion commitment. Single tank rigs can be finned up and weight belts droped. Deco divers dont have the option to fin up or drop weight belts.




In 2003 at a depth of 100m outside the blue hole in Dahab a diver pulled the inflater straight off his wing type bcd. He sunk to 120odd m before Jo Davin (TDI Instructor) managed to catch him and lift him back to his first deco stop.

In 2004 my friend Pete had his elbow to the inflater hose snap off because the plastic had perished. Fortunately it happened during cleaning

In 2006 Clare Gledhall pulled the inflater off her Halcyon wing in Vobster

In 2006 Burney decended to 65m and then hit the inflate button on his BCD. It failed no gas got through to the wing. He had to pull his twin 18s of air back up the shot.

In May 2007 anther DIR diver pulled the inflater hose off the Halcyon wing and his report on DIRX lead to others reporting similar problems. Halcyon have apparently redesigned the elbow and some retailers have done modification to prevent it occurring but there are still a lot of wings out there unmodified.
And these are just the cases i know about.




Sure if you have the option of an anchor line ascent then its doable but I have done plenty of wet suit diving in the red sea with no anchor line ascents. My two deepest dives in the Red Sea on CCR were 91 and 105m both were free ascents.

When I dived with Poseidon Divers in Dahab you were not allowed to do technical diving depths without a double bladder wing or a wing and a dry suit.

This rule was apparently the result of two incidents where buoyancy was lost over 1000+m of water.

ATB

Mark Chase
What was the Mod and how can you tell by looking at the inflator if it has been carried out?? Thanks
 

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Did you read the post i am talking about multi tank deep dives involving decompresion commitment. Single tank rigs can be finned up and weight belts droped. Deco divers dont have the option to fin up or drop weight belts.

In 2003 at a depth of 100m outside the blue hole in Dahab a diver pulled the inflater straight off his wing type bcd. He sunk to 120odd m before Jo Davin (TDI Instructor) managed to catch him and lift him back to his first deco stop.

In 2004 my friend Pete had his elbow to the inflater hose snap off because the plastic had perished. Fortunately it happened during cleaning

In 2006 Clare Gledhall pulled the inflater off her Halcyon wing in Vobster

In 2006 Burney decended to 65m and then hit the inflate button on his BCD. It failed no gas got through to the wing. He had to pull his twin 18s of air back up the shot.

In May 2007 anther DIR diver pulled the inflater hose off the Halcyon wing and his report on DIRX lead to others reporting similar problems. Halcyon have apparently redesigned the elbow and some retailers have done modification to prevent it occurring but there are still a lot of wings out there unmodified.

And these are just the cases i know about.

Sure if you have the option of an anchor line ascent then its doable but I have done plenty of wet suit diving in the red sea with no anchor line ascents. My two deepest dives in the Red Sea on CCR were 91 and 105m both were free ascents.

When I dived with Poseidon Divers in Dahab you were not allowed to do technical diving depths without a double bladder wing or a wing and a dry suit.

This rule was apparently the result of two incidents where buoyancy was lost over 1000+m of water.

ATB

Mark Chase
Well there's certainly no substitute for correct weighting and solid training.

I wish it were true that every technical diver out there could manage their diving quite easily using drysuit for buoyancy, requires practice and a horizontal ascent to achieve this easily with multitanks.

If you can't then some would say use a twin bladder, I'd go for the train more option before continuing with that sort of diving. But unfortunately the majority of divers think kit will solve all their problems.
 

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A short fat well off crap cave diver. Likes wrecks
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Brian of Aquanauts

Well there's certainly no substitute for correct weighting and solid training.

I wish it were true that every technical diver out there could manage their diving quite easily using dry suit for buoyancy, requires practice and a horizontal ascent to achieve this easily with multitanks.

If you can't then some would say use a twin bladder, I'd go for the train more option before continuing with that sort of diving. But unfortunately the majority of divers think kit will solve all their problems.

I agree, divers are just using BC D's to cover up for a lack of diving skill. My father didn't use a dry suit or a BCD just a wet suit tank and webbing harness. He had no problems and dived like it for years.

Second regulators are another thing he never used they were taught to do proper buddy breathing ascents none of this "lack of skill" long hose or octo crap.

Divers today are too quick to cover up an obvious lack of diving skill with crap like back up regs, BCD's and twin bladder wings.

That Kevin Gurr fella now hes reeeeeelllyyy crap. I mean he uses back up regs, a dry suit AND a duel bladder wing then theres Mark Ellyatt theres another double wing numptie diver. Kevin and Mark should really just own up to being crap divers, tear up their dozen or so instructors certs and get some proper training.

ATB

Mark Chase ;)
 
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