Correct, loop to loop for leader to fly line. It is a common loop for offshore, reputed to be 100%. I use 25 or 20 (once I used 16 lb) fluorocarbon, start with about 5.5 feet. There are lots of videos for technique for a Bimini loop but I do the one with both my big toes to tension the loop. I’ve also used my knee.Please explain the Bimini loop versus, say Perfection - you're tying this into your "leader" and loop connecting it to your fly line? Is the Bimini loop the prefered loop knot for tuna?