Just got back from El Pescador in Belize and some great tarpon fishing. Most of the guides here prefer HEAVY leaders – if left to their own they would just spool out 10 feet of straight 80 pound Fluorocarbon and call it done – I am not so comfortable with that since my backing is 45 pound and the fly line itself is around 35 pounds!
So my perfect tarpon leader is 6 feet of 60 flouro, 2 feet of class tippet 25-30 pound with a 2 foot 60-80 pound bite tippet (I like all fluorocarbon) That way it is almost impossible to break them off but if I do need to or something goes wrong it won’t be the fly line or backing! There are a few reason I may choose to break a tarpon off, maybe a shark is interested, maybe I notice he is bleeding I use a Slim Beauty knot for the 2 knots in the leader. If the class tippet material is 25 or over I do not double up the class tippet to tie the knot, I use just the single strand. If it is 20 or below I will double following the normal directions for a slim beauty. If the 25 pound is a thick material like Mason hard nylon you can tie blod knots or variations thereof. There is no need for bimini twists in this system, it is no big deal if your 30 pound class knot breaks at 27 pounds! If you are tournament fishing or out for a world record then you need to follow IGFA guidelines and 100% knot strength becomes important.