Freediving can be a potentially dangerous sport if done without proper instruction and training on safety procedures. Always select a training partner who is competent and able to render assistance in the event of blackout.The information provided below is for reference only, and it is strongly recommended that formal training in both freediving techniques and safety / recovery procedures are obtained before taking up freediving in any form.
Quick Safety Tips
- Ensure proper warm up and preparation.
- Do not hyperventilate – use no more than three flushing breaths. After the breath hold
- Never freedive after scuba diving on the same day
- Progress slowly – no more than a few seconds or metres at a time.
- Remain relaxed during any breath holding activity and especially on ascent from a dive.
- Listen to your body – never ignore strong signals for the need to breathe.
- Do not spend time at depth or perform too many deep dives.
- Always dive within the limits of the shallowest diver within your buddy pair.
- Do not speak or move unnecessarily upon surfacing- breathe first.
- Never train alone!
Blackout and Samba Explained
One of the biggest safety issues with freediving, is “blackout”, this is often referred to as “shallow water blackout” or hypoxic blackout and is the sudden loss of consciousness caused by oxygen starvation. With deep dives, blackout can occur under the surface and usually occurs on the divers accent, within 10-15mt of the surface where, expanding, oxygen-hungry lungs literally suck oxygen from the divers blood. It occurs quickly, and without warning. Blackout can also occur when performing static or dynamic apnea in a pool, and as in depth dives, blackout in a pool can occur very suddenly.
Samba is the name given to the uncontrolled movements that occur as a result of having very low levels of oxygen in your body. They may be as subtle as a “wobble” or could be as serious as a loss of motor control mechanical movements which is the inability to control your body, and can result in the freediver not being able to keep their airway above water.
Your freediving buddy or partner should know what signs to look for, these include:
- Sudden loss of air underwater (blowing bubbles)
- An uncharacteristic change in the tempo or rhythm of the freedivers kick
- Their eyes have closed.
- They fail to respond to prompts for signals.
- Inability to continue the dive/loss of direction.
- Erratic movements
- Inability to hold themselves up after surfacing.
- PLEASE NOTE: This list is not an exhaustive list of signs, and it is possible that there could be NO noticeable warning signs of Blackout or Samba.
What To Do
Your partner should be well versed in the “tap – talk – blow” principle of post surface blackout recovery. It is preferable that they have basic CPR skills and are able to administer oxygen.
In the event of a blackout under the surface, they should be proficient in being able to secure the divers airway underwater, to prevent any water from entering the lungs and get them to the surface.
Once on the surface, you should talk calmly, blow across their face and stroke their cheeks. When a diver has blacked out it is usual for them to still have their sense of hearing, encouraging them to breathe helps kick start the brain. The sensation of feeling air across your face, also encourages you to breathe.
Blackout is very dangerous, and we do not encourage divers to “train to blackout”, they should train only within their limits. Serious harm can come from serious blackout, especially at depth or in the hands of untrained personnel.