An improved variation of the fisherman's knot, the tuna knot is a hook-to-line connection perfect for situations where a lighter mono leader is required to fool skittish fish. Originally intended for battling tuna, anglers can also use this knot to drag stubborn grouper out of the rocks, snook from under docks or striped bass from around bridges.
Double 18 inches of leader to form a loop. Feed the loop through the eye of the hook and wrap it up the doubled standing part, back toward the main line, making three turns.
Wrap the loop back over the first set of wraps toward the hook, making an equal number of turns, then feed the loop through the small loop formed by the first wrap at the eye of the hook.
Grab the hook with pliers and pull, while pulling the doubled main line in the opposite direction. Keep tension on the loop tag end as coils form. Trim the loop and the tag end of the doubled line.