Nick Pelios
Freediver, Creator
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Nick Pelios
Freediver, Creator
In the latest episode of The Complete Guide, freediving instructor Christian Daehler breaks down the critical differences between blackouts and loss of motor control (LMC), providing essential safety techniques to help protect yourself and your dive buddies. Understanding these concepts is vital for ensuring a safer diving experience.
LMC, also known by various names such as samba, gray out, or near blackout, occurs when there is insufficient oxygen in the brain to send complete signals to the body. This results in difficulty breathing and convulsive, shaky movements. Signs of an LMC include shaky or stuttered breathing, inability to maintain coordinated movements, and the mask bouncing up and down as the diver attempts to breathe through the nose. An LMC can look different for each person, but recognizing difficulty breathing and body tremors is key to identifying the issue.
A blackout is more severe than an LMC and occurs when the brain shuts down due to lack of oxygen. It can be compared to a phone losing power—the body goes into a conservation mode to protect itself. Some key physiological responses include immediate relaxation and exhalation of air, automatic closure of the mouth to protect the airway, and potential terminal gasps, which are last-ditch efforts to breathe. The most significant risk of a blackout is the possibility of inhaling water, which can lead to drowning if the diver is not rescued promptly.
The number one rule in managing both LMCs and blackouts is to protect the airway. Preventing water from entering the lungs greatly reduces the risk of long-term consequences. When managing an LMC, it is important to secure the diver by grabbing their upper arm near the armpit and leveraging their body upward. Supporting the head by placing a hand beneath their chin helps prevent their face from touching the water. Encouraging breathing with calm verbal prompts such as "breathe, breathe" is crucial, as divers experiencing an LMC are often confused and may not realize the need to breathe.
When handling a blackout, underwater rescue involves performing a "head sandwich" technique by placing one hand under the chin and the other on the back of the head, ensuring the mouth and nose are sealed. Once at the surface, laying the diver on their back and keeping their face out of the water is essential. Removing the mask while pinching the nose helps prevent water from entering the airway. Revival techniques include tapping the diver's cheek, blowing air across their eyes, and encouraging breathing by calmly instructing them to take breaths.
Always dive with a trained buddy who understands proper safety procedures. Avoid diving with a snorkel in your mouth to ensure your airway can close naturally in case of a blackout. Practicing proper recovery breathing techniques can help prevent LMCs. Recognizing early warning signs of hypoxia and surfacing before experiencing an issue are critical measures for staying safe.
Freediving safety should always be a top priority, and understanding the differences between blackouts and LMCs is crucial for all divers. Whether you're a beginner or an experienced diver, knowing how to identify and respond to these emergencies can make all the difference in ensuring a safe and enjoyable diving experience. Stay safe, stay informed, and always dive within your limits.