I was using a 1oz head in 55m on the weekend with a 5" plastic sometimes it goes straight down no worries other times the current gets it I use 6ft of leader with a double uni knot and tied straight to the leader, if you're lucky the fish will eat it when it gets to the bottom otherwise just lift the rod up and let it back down sometimes they eat it while it is just sitting in the rod holder. I like to use Zmans with a bit of X-factor in the cavity. Good luck