Controlled Buoyant Lift

[jw2013]

I am looking for advice on performing a Controlled Buoyant Lift.

When training I did one and was told it was too fast. I repeated it and again, too fast. I also got into trouble for finning up during the lift.

I was lifting a girl in the club pool, I was weighted and she was not. As I was inflating her BC, it seemed like it was taking an age to get ME lifted from the bottom - she was beginning to float. I helped myself up by finning and I think a combination of this and the air expanding in her BC caused the lift to happen too quickly.

Does anyone have any advice on how best to perform this safely and correctly?

Thank you in advance!

 

[DevonDiver]

Here's my personal approach:

1) Establish tank knee-cradle control position (safety for rescuer, even if seemingly unconscious).

2) Reach over left shoulder and take control of the victim's LPI with left hand.

3) Reach under right shoulder and secure victim's regulator with right hand.

4) Establish if victim as air in cylinder. If so, deflate own BCD and inflate theirs ''just enough'' to start a very slow ascent. If not, deflate their BCD and inflate yours sufficiently to initiate and ascent.

5) Control ascent rate through venting BCD as you rise. If necessary (ascent stalls), add air. Small button manipulation... no over-dumping/over-inflating.

6) A controlled, accurate ascent rate is easily achievable with practice.

7) On reaching the surface, fully inflate BCD and begin normal rescue protocols from that control position.

 

[danvolker]

I am looking for advice on performing a Controlled Buoyant Lift.

When training I did one and was told it was too fast. I repeated it and again, too fast. I also got into trouble for finning up during the lift.

I was lifting a girl in the club pool, I was weighted and she was not. As I was inflating her BC, it seemed like it was taking an age to get ME lifted from the bottom - she was beginning to float. I helped myself up by finning and I think a combination of this and the air expanding in her BC caused the lift to happen too quickly.

Does anyone have any advice on how best to perform this safely and correctly?

Thank you in advance!

If you are trying to lift a non-responsive diver that is very heavy....you may very well need to inflate their BC.....HOwever, you should not need or want to inflate BOTH BC's for lift, as that means twice the control issue for dumping air on the way up....

From a perspective, the last thing a good diver wants to do, is to use the BC as an ELEVATOR....It is on you so you can be neutral, so that you can swim upwards....you should not be trained to ascend by BC alone without finning--that is horrifyingly STUPID.

So you need to get the other diver close to neutral, and yourself maybe somewhat negative( so that you wont have a great deal of positive flotation to fight with as both BC's begin to gain more lift on ascent.

I would say the better way to do this, is to keep yourself a bit negative, and try to work her BC more continuously, to keep her as close to neutral as you can....it would be a lot of task loading for you to keep both BC's exactly neutral at all times in the ascent--which would be better still, if you can do this without overload--otherwise, worry more about hers ( and your own you should have much better instant knowledge of for when to dump and how much to dump--so it won't take as much concentration)..;.much of this drill is about how much concentration and peripheral awareness you can maintain..thus my suggestions.

But again...good divers do NOT use their BC's as elevators to ascend. They swim up slowly. You use your BC to get dead neutral--meaning that during ascent, you are dumping a little air every few feet. If you are capable of ascents in a flat horizontal body position, this also makes the air dumping easier to control ascent speed with, as your body is like a wing that holds you against sudden upward movement--if you are head up, this is streamlined for rocketing up.,,When ascending in a flat horizontal, you use the rear or back dump on your BC---and you would need to use the other diver's chest dump( in all liklihood, you wont find it feasible to use their rear dump, and you wont be able to get them horizontal).

 

[maniago]

Since you mention "pool", I can tell you that in the rescue class we teach, we aren't super anal about how we get the person to the surface - a squirt of air in the BC to help and finning is expected and logical - you use all assets available when its an emergency; nothing that works is off limits. Flawless technique and a dead person is a failure.

It is understood that if you are dragging someone from 100' you do the appropriate rate ascent (without safety stops obviously). But in a pool, things are so compressed, its hard to make it realistic without dragging it out needlessly.

 

[DevonDiver]

you should not be trained to ascend by BC alone without finning--that is horrifyingly STUPID.

Well, that wouldn't be a controlled buoyant lift, now then.... would it?

The emphasis is, of course, on the word "controlled". That word does not endorse an 'elevator ride'.

With proper training and practice, it is a cinch to perform. It reduces rescuer stress, because they are in control, in position and not having to exert themselves. Fining up tends to cause more problems, legs bashing against the victim etc etc.

The secondary benefit of controlled buoyancy, is that the victim remains positive. If, for some reason, the rescuer was forced to disengage, the victim would continue rising to the surface. Not ideal... but the opposite case...the victim drifting down again, is a recorded factor in several scuba fatalities. Accident analysis has to be accorded some respect...

 

[PsyWulf]

We trained in Rescue to use the Victim's BC first,finning and own BCD secondary. Takes practice but its definitely doable. Try having a wrist computer in view on either arm and monitor the ascent rate. Safe ascent is more important than speedily getting somebody to the surface - they are already in a better position from assistance,slow or not

 

[Hickdive]

From your other post it appears that you're taking the BSAC Ocean Diver course.

If this is the case then you can ignore DD's suggestions above - that isn't how the skill is taught within the BSAC (this isn't an arguing point; it just isn't how BSAC do it so there's not much point in discussing alternative techniques that aren't taught). At Ocean Diver level you are taught how to make a controlled buoyant lift on a casualty who has air available for inflation of their BCD.

Firstly, YOU need to be neutrally buoyant as this is your likely buoyancy condition on finding a casualty that requires lifting.

Secondly, a lot of instructors will have the training casualty negatively buoyant* as this is the likely buoyancy state of a real casualty (a positively buoyant casualty in a real case, which isn't particularly likely, will have floated to the surface with no rescuer involvement)

Maintain your neutral buoyancy as you ascend by dumping air appropriately from your BCD.

Do NOT ride your casualty's buoyancy to the surface. If you do and you lose contact they will make an uncontrolled ascent whilst you make an uncontrolled descent because you will be negatively buoyant and they will be positive. That can possibly harm the casualty further and put you, the rescuer, in danger. That is NOT a controlled buoyant lift.

Do NOT drag your casualty to the surface using your own buoyancy. If you do and you lose contact they will make an uncontrolled descent whilst you make an uncontrolled ascent because you will be positively buoyant and they will be negative. In typical UK visibility you may then have to re-descend and search for a casualty who is probably not emitting any tell-tale exhaust bubbles to help you locate them. In real life incidents where this has occurred the result is invariably that the casualty dies.

So, approach the casualty, make a positive grip on them and their bcd controls. Add air to their BCD until they start to lift. Often you'll find they stop as they come off the bottom - don't be afraid to additional short squirts of air to keep them moving at this point*. Once the ascent has started dump small amounts of air from their BCD to control the rate of ascent and occasionally from your own BCD to prevent you from becoming buoyant.

DO NOT FIN UP! You can push off the bottom to start your own BCD air expanding but your ascent should be neutral/slightly buoyant as far as possible. Finning can cause the ascent to be too fast, it can also disguise the fact that you may have dumped too much air from the casualty, they have become negatively buoyant and you are now trying to swim them to the surface. This is exhausting (see if you can find someone who took the ancient BSAC "Deep Rescue" test) and you want to save your energy for for further rescue actions on the surface.

Whatever you do when adding or dumping air to either BCD do it a little at a time and see what effect it has before adding or dumping again. Often you will find that rescuers trying to dump air forget about the casualty's upwards momentum and dump air from an ascending casualty until they stop ascending. That inevitably leads to them sinking back down again as they have actually become negatively buoyant and only momentum was carrying them upwards.

*the Sub-Aqua Association (another UK training agency) actually uses a negatively buoyant dummy in scuba gear for their rescue training.

 

[danvolker]

Well, that wouldn't be a controlled buoyant lift, now then.... would it?

The emphasis is, of course, on the word "controlled".[snip]
.

Right ..... so ideally taught by instructors kneeling on the bottom, and wearing 2 or 3 BC's for redundant elevators

I get that this is aimed at low skilled students....However, my advice was to keep the non-responsive diver close to neutral while swimming up....which means this diver is constantly becoming more positively buoyant, and is constantly requiring the student to dump some air out....in your scenario, if this assisting diver gets suddenly challenged on the ascent, they would then stop dumping, and the non-responsive diver gets no more dumping, so the non-responsive one begins their positive ascent by themself if the assisting diver loses them. ( some of this is semantics in how you or I communicate an idea)....

As to how easy it is for a well trained diver to ride an elevator up properly....sure, it is easy when they are paying close attention--which we know does not always happen with many divers...but as you said, the skill is simple....With new divers, in sensory overload and little peripheral awarness----I think this is a recipee for polaris missile ascents, and worse still, it allows them to think that it is OK to Ride the BC up to the surface in their own ascending future--which it is NOT

 

[DevonDiver]

In training, ascents should be exaggerated slow. That's a safety/liability issue. In a real rescue, with a non-breathing casualty, speed is utmost. 18m/min is a 'safe' ascent rate from a recreational dive - it really is, in this context. I, personally, think there's many scenarios where I would risk even faster.

Again, context is everything; dive depth, how long the casualty (corpse?) has lacked respiration.... whether it's your ex-wife..

 

[maniago]

.... whether it's your ex-wife..

...or your current one...!