Most guys use the #1 dipsey and there is a dive chart that comes with every dipsey you buy.They work best when you can run 2 on one side of boat.Using identical rods,you can see any difference in the curve of the rod or the angle of your line into the water.That way you can tell if a smaller fish is on the line,even if the dipsey didnt release.The line most guys use is Hi Vis Yellow power pro braid @ 30#.