Why Controlled Buoyant Lift training works

Photo credit: Simon Rogerson

Analysis of scuba diving incidents has shown how effective the Controlled Buoyant Lift (CBL) is when used in an emergency situation.

The 2023 Incident Report revisited the efficacy of rescue techniques in resolving incidents. Of particular interest was that where CBL techniques were reported to have been used in recovering an incapacitated diver, as opposed to in a training environment, we recorded a 100% success rate over a 10-year period. 

Table 1. The efficacy of rescue techniques used in reported incidents

1. Analysis from data from 2014-2023 inclusive
2. Data extracted from the entire database
3. Successful outcome defined, for AS, as the casualty reaching surface without having to use free ascent; for CBL as the casualty reaching surface and for resuscitation techniques as the casualty regaining consciousness

The report acknowledges:

The result of this analysis is a reflection of the excellent training programmes delivered by excellent diving instructors who, in turn, ensure divers are well trained in rescue techniques. There is little doubt that the competency with which divers deploy these rescue techniques saves lives.

That in no way implies there is grounds for complacency and divers and instructors should continue to practice and refresh skills to ensure that if called upon they remain of a high and consistent standard.

Recognition and Reaction

During diver training, and any subsequent refresher practice, the control element of a CBL is clearly important, because what you don’t want to result is either the rescuer or simulated casualty suffering an injury as a result on an uncontrolled ascent. It is partly for that reason that BSAC insist that the instructor does not act as the casualty and should maintain a position to remain in overall control of the lift and to intervene to control the ascent if it becomes necessary. That means staying with the lift at all times throughout the ascent. 

Effectiveness

In training you are prepared for the need to institute a lift but in real diving you rarely get any warning of such an action being necessary. That is why it is important to over practice the skill and when you encounter different kit configurations you should carefully consider how that might impact on a rescue, and if necessary, rehearse those actions in the water, perhaps towards the end of a dive. To the same extent should the need arise, you should not delay the ascent. We often see training for a lift start with dumping the buoyancy of the casualty before inflating a chosen source. Such action introduces an unnecessary delay to the ascent. 

Likewise on surfacing the important action of providing positive buoyancy can be misinterpreted. Many may recall the good old ABLJ which where fully inflated it ensured the casualty remained face up in the water. Many BCD’s and wings used today will not always do that and over-inflation can result in the casualty, and/or the rescuer, being pushed forward and even face down. Consequently, the training programme has been adjusted to advise 'Adjust casualty’s BC to provide sufficient but not excessive buoyant support.'

Urgency

In the real-life situation where an unresponsive diver requires to be lifted to the surface an appropriate degree of urgency should be applied. Controlling the ascent rate remains important to ensure not only the safety of the casualty but also the rescuer. However, especially in the case of an unconscious, non-breathing casualty or a diver suspected of suffering from IPO, non-mandatory precautions like Safety Stops should be omitted. It is especially important in cases of IPO that the rescuer remains with the casualty all the way to the surface and prepared to initiate rescue breaths and recovery as soon as possible.

Safe diving guide

Stay safe – dive safe

Jim Watson
Safety and Development Manager