In the past, I've used (with some help and advice) 15/17 pound test with about 4 feet of 30 pound test mono leader for blues. But this wasn't with live bait. I've heard fluorocarbon leader is absolutely horrid to knot, so I wouldn't suggest it. You'd prolly want to use the lowest test line you can get away with. You can fit more on your reel, it's easier to knot, and you can feel the hits way more easily. I've also heard of a good rig for livelining bait -- 2 hooks attached somehow to a central location -- one to put thru the mouth, and another to slide thru the dorsal fin. Never seen the thing, though, so I couldn't tell you exactly what to look for. I know the blues always snag the butt end of whatever I'm fishing with, so having a hook further back may keep you from reeling in mackerel heads all the time. I have a buddy that uses live bait -- next time I see him, I'll ask what he uses and get back to ya. Good luck!
