I went on a charter with a mate up to qld and he managed to lose his leader on a big one. He wasn't feeling to good as the humidity and the swaying got to him so i tied his rig for him. Double uni knot 100lb braid to 200lb leader and uni knot to the solid ring for jigging. He managed to hook up to a 3m+ shark fought it over an hour and the leader wore through eventually. Double uni fully intact, leader totally destroyed. Never had a double uni fail. I always do 5 turns with fluoro/mono and 8 turns with braid.