I use a RAM trolling motor attachment on my gunnel to keep the TM from bouncing while under way. A longer shaft like mine (60") will bounce bad if not secured. I run my collar up against the head 99% of the time.

https://www.walmart.com/ip/Ram-Mount-Trolling-Motor-Stabilizer/20836083?wmlspartner=wlpa&selectedSellerId=0&adid= 22222222227015030809&wl0=&wl1=s&wl2=c&wl3=40968785 192&wl4=aud-310687322322:pla-78911658632&wl5=9014668&wl6=&wl7=&wl8=&wl9=pla&wl1 0=8175035&wl11=online&wl12=20836083&wl13=&veh=sem