SWB Shallow Water Blackout By Michelle Brislen What

SWB Shallow Water Blackout By Michelle Brislen

What is SWB? Loss of Consciousness while in water Usually caused by hyperventilation while freediving or breath-holding Often happens to freedivers, athletes, and good swimmers. Can happen in the ocean, pools, lakes, rivers, etc.

“Hero Worship” Image from NY Times

Energy Processes Cellular Respiration C 6 H 12 O 6 + 6 O 2 Sugar Oxygen 6 CO 2 + 6 H 2 O + Energy Carbon Dioxide Water

How does it happen? Release of CO 2 (Carbon Dioxide) through hyperventilation or deep exhales When under water O 2 (Oxygen) is used up and turned in to CO 2 is lower than normal because of hyperventilation thus decrease urge to breathe Stay down/under water longer and O 2 continues to be used and deprives brain Blackout occurs

Normal Dive SWB Dive Problem Diagrams from Wikipedia

Shallow Water Blackout Diagram from Aquatics International

How to Prevent SWB Do not hyperventilate Do not have breath-hold competitions under water Do not perform underwater laps When you feel the urge to breathe, begin your ascent “Leave something in the tank!” Dive with a Buddy!!!! Maintain watch for 30 seconds after surfacing Be weighted correctly and willing to release your belt if you’ve pushed it too far. Tell your friends! Adults too!

References shallowwaterblackoutprevention. org “Confessions of a Freediving Spearo” by Sheri Daye; Hawaii Skin Diver Magazine 2010 www. aquaticsafetygroup. com/PDF/Dyingfor. Ai r. Aquatics. International. February 2005. PDF www. aquaticsafetygroup. com/PDF/Shallow. W ater. Death. The. Combat. Edge 2003. pdf www. wikipedia. com