On the 27th October, 2013, Carlos Burle saved Maya Gabeira's life at Praia do Norte, Nazaré, Portugal. Maya was out in big surf when she had a near-fatal accident. Carlos pulled her from the water and started cardiopulmonary resuscitation (CPR).

Andrew Schmidt, director of Lifeguards Without Borders, issued a simple statement in response. When an adult is suffering a heart attack, he or she is having a cardiac problem. Circulation has "stalled", and blood has stopped pumping around the body. Heart compressions are needed to restart the blood flow.

Now, what is drowning? The primary cause of injury and death by drowning is a lack of oxygen to the brain and vital organs. The primary goal of treatment in this case is to provide oxygen.

The difference between a person who is drowning and someone suffering a heart attack is important to recognize, because the wrong treatment can actually do more harm than good. A heart attack victim may need mouth-to-mouth resuscitation as well as chest compressions only if he or she has also stopped breathing.

Conversely, you should never carry out chest compressions on a drowning victim unless no pulse is detectable. Proper chest compressions are extremely intense and can hurt or kill. So be sure. Check. Double check.

You can be of great value in the water if you understand the basics of resuscitation of a drowning victim. The most important thing is not getting water out of lungs, but providing oxygen. So rescue breaths are critical.

"Whether it is mouth-to-mouth or pocket mask, you're going to do the greatest amount of good," says Schmidt.

Learn basic drowning treatment for surfers. Also, take a look at the health risks of big wave surfing.