Here is a PDF from Terry Maas with some excellent information regarding freediving blackouts and a new product, now under development, that is being designed to save lives.
Chad
http://www.freedive.net/swb.htm
Also two other threads about it on other forums.
http://www.spearboard.com/showthread.php?t=25855
http://forums.deeperblue.net/forum53/thread64975.html
Chad
http://www.freedive.net/swb.htm
Also two other threads about it on other forums.
http://www.spearboard.com/showthread.php?t=25855
http://forums.deeperblue.net/forum53/thread64975.html