Free-diving rescue in water.
The vast majority of loss of motor control(LMC) or blackouts happen on the surface though sometimes on rare occasions they can also occur as the diver nears the surface. In the last ten metres the diver should be accompanied by the safety diver who stays within arm’s length.
The safety should be alert enough to notice any signs of excessive fatigue or overexertion and provide assistance to the tired diver. If blackout occurs before this can happen the safety should come behind the unconscious diver and reach under their armpit and across their chest with one hand while the other arm supports the head, holding it in such a way that the airway remains closed. This is to avoid entry of water into the lungs. The rescue diver should fin towards the surface in a sideways position to the victim. This allows greater freedom of movement for the rescue divers fins. It’s very important that he tries to come up at the safety buoy as this will help lessen the shock to the victim as he comes around.
On the surface the victim should be supported with one hand holding his head well up out of the water in such a way that his airway is fully open. The other hand will very gently slap his face while the rescue diver repeats in a soft voice ‘breath, breath’. The hearing sense is the first to come back after black out and it is very important that the rescue is done in a calm and reassuring manner. The victim may be in a state of disorientation and it is essential that there is nothing done to cause further shock.
Bringing them around gently.
Black out is the last attempt of the body to preserve O2 for the heart and brain as unconsciousness reduces use of O2. Once the body is in a place where respiration is possible i.e. the surface then breathing will resume naturally. We avoid loud noises or abrupt movements because the victim while unconscious is in a vulnerable place and the unconscious mind will react against any situation that seems traumatic by prolonging unconsciousness.
The affected diver should rest and definitely not dive again that day as there is increased risk of black out after having LMC or blackout. Very often the diver will not be aware of having lost motor control or blacked out. In the water there is no need to make a big deal out of it, wait till you get back on the boat or dry land to discuss the matter. It is important that any lessons that need to be learnt are learnt, but we should avoid a situation where the experience becomes something traumatic. There should be no blame or recrimination. It can happen to anyone.