Stern planers are just a floating device to add rods to your set up. They were originally made for river anglers out in washington for trolling way behind the boat and to stay in line. As salmon spooked out from under boat they would come back to sweet spot as lure came along way behind the boat. Tad pole are a diving inline wieght. Much like stingrays or bottom bouncers with a steeper dive cure and wieght transfer to reduce pull when a fish strikes.