I noticed making noise to attract perch has been mentioned a couple times in this thread. My dad and I use to fish with a guy 30 years ago that had a homemade "fish call" he used perch fishing. It was 3 of the old metal window weights (the ones that were hidden in the wall on the sides of the windows) tied on a long rope. He would lower it off the back of the boat and tap it on the bottom every so often. I swear the perch use to start hitting within a few seconds - of course I was 10 years old at the time and I may have just wished it was working. He would also start and rev his motor occasionally to make a little noise.
Anybody ever hear of anyone doing this sort of thing......because I happen to have a few window weights in my barn as was thinking about trying something similar but don't want everyone on the boat laughing at me.
Butch & Denny's sells perch callers or they did. Works similar to what you described but the action of the boat rocking makes them work.
Wakina
23 foot Pro Line
HDS 5X Sonar
HDS 5M GPS
Navonics chip, model #DMSD/649P+
Platinum Plus Lake Erie and Lake St Clair Marine.
Raymarine Dragonfly7 Sonar-Downvision-GPS combo with chirp technology.
Navonics Hotmaps Premium East chip