Widely used for both freshwater and saltwater applications, The Double Uni Knot is used to connect two lines of the same or varying strengths with approximately the same diameter.
The Double Uni Knot is an excellent knot for tying braided line to monofilament or fluorocarbon, making it a popular choice for joining leaders to main lines. When tying your knot, just be sure to make several extra wraps with the braided line (which is more prone to slippage) than you do with the monofilament or fluorocarbon line.
1. Overlap the ends of the lines you want to join. Then, take the end of the line from the left and double back and make three to four wraps around both lines and through the loop that you formed. Pull tag end to tighten.
2. Now repeat the same steps with the end of the line on the left, using the same number of wraps (unless you’re tying braid to mono or fluorocarbon, in which case you should double the number of wraps).
3. If you have followed these steps correctly, you should have two Uni knots. Wet the strands between the two knots, then pull the two lines in opposite directions to slide the two knots together. When tied properly, the two knots should butt up snugly against each other and be cinched down.
4. Clip the ends close to the knot.