AV on a man in a wing

[NeilB]

I have been talking to one of our new Dive Leaders and he complained about having to perform AV in the water on a man wearing a wing. As he said, a wing is ideal to keep you level in the water but it is designed for you to hang underneath it. So when he inflated the wing, dumped weight belt and then twisted the casualty to perform AV, the casulty had a tendancy to roll over onto his front - all the bouyance after all is under the casualty. It was all he could do to hold the casulty face up and perform AV at the same time.

So my question is - has anyone else faced this problem and if so how did you get round it?

[David Walker]

If the wing is providing enought lift, why dump the weight-belt?

Go on tell me "Because its in the book".

We just spent the weekend doing all (well, some) of the Dive Leader dives and did all the rescue bits - I certainly wouldn't drop the weightbelt while towing so long as the cusaulty wasn't so overweighted that they were too low in the water... apart from anything else we'd have to go back down to 15m to rescue it! The only time it was necessary to drop the belt was just before chucking the casualty into the boat (well, the quay in Stoney), and doing one or two repetitions of AV without the weightbelt won't be much of a problem.

Another thing occurs to me, about the 'it's in the book' comment, is that I seem to remember (although could be wrong) that i've seen somewhere within BSAC documents, or maybe it was mentioned by one of the instructors on my IFC, one of the two anyway, but that when towing it was often recommended to leave the weightbelt on even with people in BCDs because of the advantage to the position in the water. I suppose with the weightbelt usually around the waist and the bouyancy higher up, it'll tend to bend the body upwards a bit so that the head may be a bit better kept out of the water...? And of course keeps them more stable in most situations, less rolling around.

David

[janos]

So my question is - has anyone else faced this problem and if so how did you get round it?

It happens to be all the time.

I wear a wing and have faced this problem when it's fully inflated on the surface, especially when using a single tank. I find that with my wing (DiveRite Rec wing) it only needs to be half-inflated for my head to be well clear of the water, even while wearing a weightbelt.

So in addition to not dropping the weightbelt maybe only partially inflating the wing is a solution?

Laters,
Janos

[iainmsmith]

I have been talking to one of our new Dive Leaders and he complained about having to perform AV in the water on a man wearing a wing. As he said, a wing is ideal to keep you level in the water but it is designed for you to hang underneath it. So when he inflated the wing, dumped weight belt and then twisted the casualty to perform AV, the casulty had a tendancy to roll over onto his front - all the bouyance after all is under the casualty. It was all he could do to hold the casulty face up and perform AV at the same time.

So my question is - has anyone else faced this problem and if so how did you get round it?

Could it be that the wing is too large for the cylinder(s) in use? I've certainly never noticed this problem when doing AV drills on divers with 27 or 36lb wings (on 12L and 15L tanks) or on twin 12s with a 45 or 55lb wing.

On a purely pedantic note, I would point out that the buoyancy is not all under the casualty - a significant part of it will be made up of the casualty themselves and their thermal protection. Also, the tank(s) normally act as a pretty effective keel in this situation.

Iain

[NeilB]

On a purely pedantic note, I would point out that the buoyancy is not all under the casualty - a significant part of it will be made up of the casualty themselves and their thermal protection. Also, the tank(s) normally act as a pretty effective keel in this situation.

Iain,
you can be as pedantic as you like :-) Unfortnatly out here in the Middle East thermal protection consists of a T Shirt and shorts! The casualty concerned is not so naturally bouyant as I am (larger chap...get the drift) so maybe the combination of 11l aluminium tank, skinny bloke and large wing was just too much?

I will give a go myself this weekend and see how I get on...wish me luck.

[jens hucke]

I agree that inflating the wing as little as possible might be of some help.

The position of the cylinder can also have an effect. If aluminium and empty, positionned low on the wing, it will offer bouyancy, tipping the casualty forward face down. If mounted higher, it might be clearer of the water earlier, hence offer less bouyancy, and less forward thrust. It might be a subtle difference, but worth experimenting with.

Finally with the small amount of lead your diver should be requiring when just wearing a T-shirt, part of it might be better relocated onto the cylinder itself, especially if you try to move the cylinder up and need to adjust trim as a consequence. Dual benefit.

I would be interested to know how you get on, should you decide to try it.
Thanks and good luck
jens

[rogersides]

I had a similar experience when doing my DL assesment.

I found that it was hard to roll the casualty due to the wing. The best method seemed to be to push down on the top of the wing, behind the casualty's head, which pushed the body flat, and rose myself out of the water enough to be able to be able to get a good seal around the casualty's nose.

It's harder work than rolling the casualty in a BCD, but it worked for me.

I'm glad that i had this slight challenge for my assesment, as in a rescue situation you can't choose what equipment your buddy will be wearing.

cheers,
Roger

[iainmsmith]

you can be as pedantic as you like :-) Unfortnatly out here in the Middle East thermal protection consists of a T Shirt and shorts! The casualty concerned is not so naturally bouyant as I am (larger chap...get the drift) so maybe the combination of 11l aluminium tank, skinny bloke and large wing was just too much?

Ah...and there's me with my UK drysuit-and-steel-tanks mindset. Sorry!

It occurs to me that AL tanks are normally buoyant anyway. Add a large wing and I can see the potential for a problem.

Iain

[terryh]

I have been talking to one of our new Dive Leaders and he complained about having to perform AV in the water on a man wearing a wing. As he said, a wing is ideal to keep you level in the water but it is designed for you to hang underneath it. So when he inflated the wing, dumped weight belt and then twisted the casualty to perform AV, the casulty had a tendancy to roll over onto his front - all the bouyance after all is under the casualty. It was all he could do to hold the casulty face up and perform AV at the same time.

So my question is - has anyone else faced this problem and if so how did you get round it?

Easy, dont dump the weightbelt. The book says you dump it, but the extra ballast keeps the casualty more stable.

Also dont push straight down! Left hand goes on pillar valve
(I have grab handles on my cylinders), right has forearm over
casulties right arm (you can do cupped or pistol grip).

Imagine the casulty is on a spit and rotate along the
centerline. With a combination of turn left hand and push down
slightly on right forearm the casualty will rotate towards you
and you can meet him/her halfway. Very effective and very easy
to do.

NB: This must be a combination of rotate and push down. Not
just push down. We want to turn him, not dunk him!

TerryH

[Ben Field]

> Also dont push straight down! Left hand goes on pillar valve
> (I have grab handles on my cylinders), right has forearm over
> casulties right arm (you can do cupped or pistol grip).

IIRC The "book" method makes a point of saying NOT to put your arm over the casualty. Your right elbow should be tucked into your chest and your hand coming up the right side of the casualties jawline. This is required for proper neck extension.

Rotating them like a spit is correct and either the tank valves or far shoulder will work. I find this drill easier in full kit than in the pool due to the suit, perhaps coming from a warm water diver this question is more about adressing the different technique required when the diver has less buoyant equipment?

This whole thread sounds like the original casualties wing/cylinder combo was incorrectly setup/weighted, remind them that not only should their config work underwater but in a rescue situation also. Big wing + Ali tank is a recipe for diasater IMHO. Wings come in different sizes, get the right size.

BEN

[terryh]

IIRC The "book" method makes a point of saying NOT to put your arm over the casualty. Your right elbow should be tucked into your chest and your hand coming up the right side of the casualties jawline. This is required for proper neck extension.


AFAIK the "book" method, is very much an attempt to stop
students "dunking " the casualty by pushing directly down with
the forearm.

But .......
Students are always taught that the push is on the
casualties right forearm/edge of right shoulder and NOT to dunk,
but enable the rotate by pushing against the action of your
left hand.

This works extremly well and if performed right, there is NO
danger of dunking.

Rgds
TerryH