I've looked at this Hydrowave product myself and I have to say, I'm very intriqued by it. It may be a hoax, but I think there could be possibly something to it. I can see where it would be beneficial in some methods of crappie fishing. I don't think it'd be very productive for long lining as the boat would be moving and covering too much ground. I do think it could help make a few fish bite while spiderrigging or fishing brush piles. I know there's a lot of times I mark fish and have bumps and I'm confident that they are crappie not "feeding." I've tried scents and live bait and that seems to help sometimes, but if there were something to trigger the "feeding instinct" in fish that could be remarkable breakthrough in fishing technology....this could be it!