They have their time and place.. if absolutely nothing else it can help mask the noise of the boat and trolling motor. I've been in the boat with Fouzman and Mark Pack when turning the hydrowave on moved an entire school of fish from one side of SRA point to directly under our boat. We were fishing the area for 15 minutes with zero bites watching the folks on the other side of the point catching the snot out of em. Turned on the Hydrowave and in a short time the folks across from us weren't catching anymore and we couldn't get a bait to the bottom without catching a fish. Coincidence? I'm going with no.