I can't speak for Crappie fishing because I haven't been Crappie fishing since I got one. But, I am a believer for Bass fishing.

Do you remember the Color-C-lector crankbaits? I think Bagley's and Rebel made complete sets of them for Dr. Hill's color spectrums......Bass Pro sold them in their catalog for years.....

I have had one for little over 2 years and truly believe in it have not tried it for crappie but you gave me an idea. The way it calls bait fish up around the boat I can't see how it couldn't help. Also their customer service is 2nd to none.

I have found they work best when you are around fish.

When you are not around fish they are pretty much useless.

I have also found a 9/16" socket is ineffective on a 1/4" nut.

The statement that the hydrowave is another tool is exactly correct. There is no guarantee it will help you catch more fish but like lures and any other tool in the right situation and used properly it will help activate the fish. The key is there are different sounds and they may not all work in a certain situation. You have to find the right sound.
Ron

I see this your way Ron for sure and like I said earlier predator fish have to be present as well. If tuned right I could see where this would be really good when fish are schooling, especially if you could draw the school of bait fish they are chasing to your boat.....on the opposite end of the spectrum; say when you have conditions like today and they aren't feeding aggressively at all, it would just be a noise maker.......I think this is something that you have to know "when" and "how" to use it.......