Old timers trick from many decades ago ........... In cold spring waters they would just cast a plastic worm out with very little weight and just .let it sit ........ And sit ...... And sit ....... Minutes at a time. Then raise the rod tip and move it about a foot and do it again ............ Tough to let it sit that long but those that did caught lunkers ....... They fished dark rock piles that stuck out of the water because it warmed first and warmed the water there first