I used those in
SC last year fishing from a boat. I hooked into a nice 6' or so shark, Fought him for about 20-30 min got him to the boat twice before he ran again. The second time he ran, and stopped about 50 yards off the boat, surfaced then dove again. On the dive the line went slack, when I reeled it back in the crimp on the leader or the leader itself broke and all I came back up with was a swivel.