I got new one on the cheap via ebay...I do believe they work...my friend Jon Schwartz tested it on a Tiger shark in Kona and it worked...if you are married with kids and have a good job and you kayak offshore then it is a good extra protection to have especially with the HUGE increase in seals...
http://www.sharkshield.com/blog/jon-...ifornia-usa/20
BTW most kayakers or guides will not talk about their GWS close encounters except to close friends..
Did you see a GWS?