Waterlust ambassador @deepleigh monitors the entrance of an underwater cave in the Florida springs while the rest of the team explores below. Freediving is inherently dangerous because of a phenomenon called "shallow water blackout", also known as cerebral hypoxia. Normally the urge to breathe is triggered by high levels of carbon dioxide in the body, but if you saturate your body with oxygen and remove carbon dioxide through breathing techniques before a dive, this trigger may not occur. In this case a diver may feel completely at ease with no physical urge to breathe despite their brain being desperate for oxygen. The blackout comes suddenly and unexpectedly, which is why you should always have a safety partner watching you in case you pass out!