This handy little knot is definitely one to know how to tie because there are times when a float rig will be the best option for catching a few sea fish, and you will need to use some form of a knot to prevent sliding floats from riding all the way up your mainline.
Although this can be tied using another length of line, using powergum is better. Powergum is a thick rubber-like like having a little stretch, so when it's pulled tight it really bites onto your mainline ensuring that the knot doesn't slip and slide along the line.
This knot can be tied onto your mainline, at any point above the float, and when the float rig is cast out, the float will ride up the mainline until it hits the stop knot, locking the rig at the required depth.
Another great aspect of this knot is that the knot can be wound through the rod rings, enabling rigs that are set to extreme depth to be cast easily and effectively.
Here's how to tie it...