Before you get into free diving, it's important to know about some of the inherent dangers of the sport. One of the greatest risks
is blackout - it can occur in shallow water, deep water or from what is called CO2 blackout.
This diving malady is probably the biggest argument for diving with a buddy, who can support and assist you in the event that you
should black out. Unfortunately, this is the type of emergency that can't be recovered without the assistance
of your dive buddy or other surface support. When one blacks out, he becomes unresponsive. In cases of Shallow Water Blackout (SWB),
the freediver swimming towards the surface will exhibit various symptoms that will be readily apparent to the trained eye.
Signs & Symptoms of Blackout
Although there are many different signs/symptoms of blackout, a dive buddy or surface support person who isn't experienced with
this diving malady may not recognize its occurance immediately. For the diver who is ascending, by the time the symptoms begin
to occur for blackout, it is usually too late and the diver loses consciousness soon after. For the dive buddy or surface
support personnell, careful observation for the beginning symptoms or signs is paramount to a successful rescue. They are as follows:
The diver stops swimming for no apparent reason.
The diver's legs become slack.
The diver's arms may fall down to the sides of his body.
The diver's eyes may roll back or close as he becomes unconscious.
His head may roll forward or drop down onto his chest.
The diver will begin sinking.
A convulsive twitching or spasming may occur.
A diver who has succumbed to blackout will, upon reaching the surface, regain consciousness within moments of having been assisted
to the surface. However, while the diver is still unconscious underwater, he has now become a potential drowning victim. While
the unconscious diver is sinking, he has lost most of his voluntary bodily control. But, he still has protective reflexes that helps
to assist in the rescue process. One of those reflexes is called the laryngospasm.
A laryngospasm closes off the vocal cords, thus preventing water from entering the respiratory system. A laryngospasm, after time,
will relax, which at that point will cause problems if the freediver is still submerged underwater. More than likely, when the diver
has reached the surface, and by keeping the diver's head out of the water, the laryngospasm will cease and the victim's breathing will
resume.
Immediate resuscitation of the diver may be hindered at first by the laryngospasm, which will block any air entering, but it will
eventually relax and in-water resuscitation
can then begin. If water has entered the lungs, careful consideration must be given with the now near-drowning diver. Even if
he appears fine after successful resuscitation, he may still suffer from what is called a secondary drowning for up to 24 hours
after in the incident due to water residing in the respiratory system. It is strongly advised that the rescued diver who
experiences a near-drowning seek immediate medical treatment /evaluation - even if he says he feels better.
The dive buddy should always be well ventilated, or in other words,
should not be out of breath while at the surface observing
his submerged dive partner. This is so he can be ready should he need to respond to this type of dive emergency. Once the dive
partner at the surface recognizes that his buddy is in crisis, clear thought needs to be given to the appropriate response. Several
deep breath cycles or ventilations should be taken by the rescue diver to assist the unconscious diver. The following
techniques are used in the rescue process.
Assisting the Unconscious Diver
Care should be given when assisting the unconscious diver to the surface. Take care not to
startle or aggravate the unconscious diver's body, such as slapping or yelling, as this can cause the victim to stay in
an unconscious state.
The following procedures should be used on the unconscious diver:
The diver's head should be supported by cradling his neck.
To help prevent the diver from taking in more water, cover the diver's mask and mouth with your free hand (the one not cradlng his
neck).
While maintaining firm contact with the unconscious diver, swim to the surface, supporting the victim all the way.
Once at the surface, tilt the head upwards slightly to keep the airway open.
Any flotation device, such as a surface float, line or boat platform will help.
Remove the unconscious diver's mask to aid in air circulation and breathing.
Wait for the diver to regain consciousness (breathing, responsiveness to questions, etc).
Shallow Water Blackout response time is typically 3 - 10 seconds.
Deep Water Blackout response time is between 10 - 30 seconds.
Once the diver has recovered and is breathing on his own, continued observation by the rescuer is important until out of the water.
There is a possibility that the diver will surface and then blackout. Careful, detailed observation is required at all times by
the rescuers. All diving should be stopped for that day.
If the diver does not respond and fails to start breathing on his own, begin the following:
Ditch all weights and masks from the unconscious diver and the rescuer.
Start basic first aid, arousal, and open the airway to check for breathing.
If the diver is not breathing, initiate the following procedures:
Signal for additional assistance.
Begin performing artifical respiration (2 breaths initially, followed by 1 breath every 5 seconds).
Evacuate the diver from the water, either by towing to shore or to a boat.
Once on shore or deck of the boat, continue maintaining airway control, artificial respiration, and check for a pulse. If no pulse
is present, initiate CPR while continuing artificial respiration.
Activate the planned EMS (Emergency Medical System).
It should be noted that training in First Aid and CPR is a part of all those concerned in the dive activity. Your local dive shop
can provide the training that not only covers basic first aid, but dive-specific rescue techniques as well. In addition, they can
provide the training for administering O2 that can significantly increase the chances of recovery from submersed dive accidents.
